/104 2032 Santé Publique Preparation (Dr. Tol Bunkea) 1 / 104 1) If the diagnostic (confirmatory) test is expensive or invasive the best diagnostic test is: a. use a cut-point with high sensitivity b. Maximize true positives c. Use a cut-point with high specificity d. Minimize false positives 2 / 104 2) What is the correct answer about a point estimatestatement: a. .A point estimate involves the calculation of confidence intervals for some statistic b. .A point estimate involves the calculation of means for some statistic c. .A point estimate involves the calculation of median for some statistic d. .A point estimate involves the calculation of mode for some statistic 3 / 104 3) On the statements below which are validstatements of probability: a. We are 101% certain of success. b. My probability of winning the lottery is less than 0. c. Our probability of dying is 100% d. We are 150% certain of success. 4 / 104 4) Which answer below is correct about the confidence interval: a. The most commonly used of confidence interval is the 95% interval b. The most commonly used of confidence interval is the 90% interval c. The most commonly used of confidence interval is the 99% interval d. The most commonly used of confidence interval is the 100% interval 5 / 104 5) In a study of Cambodian people over 65 years of age, it is found that 255 have heart disease and 2302 do not. If a Cambodian over 65 years of age is randomly selected, what is the estimated probability that he or she has heart disease: a. 2302/255 b. 2302/(255+2302) c. 255/2302 d. 255/(255+2302) 6 / 104 6) Which below statement is not correct: a. Point estimates are not calculated from sample. b. An estimate of the parameter based on observed information in the sample c. Statistics are random variables because they differ from sample to sample d. Statistics are known values computed from a sample 7 / 104 7) On the statements below what is valid statements of probability: a. We are 150% certain of success b. Our probability of dying is 100% c. My probability of winning the lottery is less than 0. d. The probability of this patient will cure is more than 100% 8 / 104 8) What is the wrong interpretation of 95% confidence interval: a. The interpretation of confidence interval is always relates to a parameter and never a statistic. b. The interpretation of confidence interval is always relates to a statistic and never a parameter c. We can be 95% confident that the true value of population (parameter) lies within this interval. d. We are 95% confident that the true value of population (parameter) is between this interval. 9 / 104 9) What is the probability of getting an odd number when you roll a dice? a. 1/2 b. 1/4 c. 1/3 d. 1/5 10 / 104 10) If an event is impossible it has a probability of: a. one b. zero c. Less than one d. greater than zero 11 / 104 11) μ is an example of a a. Sample statistic b. Mode c. Population variance d. Population parameter 12 / 104 12) Which statement is not true about confidence intervals? a. .A confidence interval between 20% and 40% means that the population proportion lies between 20% and 40%. b. .A 99% confidence interval procedure has a higher probability of producing intervals that will include the population parameter than a 95% confidence interval procedure. c. An approximate formula for a 95% confidence interval is sample estimate ±margin of error. d. .A confidence interval is an interval of values computed from sample data that is likely to include the true population value. 13 / 104 13) The branch of biostatistics that deals with testing of hypothesis, making predictions using data collected is called: a. Test statistics b. Descriptive statistics c. Inferential biostatistics d. Comparative biostatistics 14 / 104 14) If a negative predictive value was 98%, it means that: a. Among those who had a positive screening new test, the probability of disease was 98%. b. Among those who had a negative screening new test, the probability of being disease-free was 2%. c. Among those who had a positive screening new test, the probability of disease was 2% d. Among those who had a negative screening new test, the probability of being disease-free was 98%. 15 / 104 15) តើអ្វីខ្លះជាផ្នែករបស់ Descriptive statistics? a. Measure of dispersion b. Measure of central tendency c. Range & median d. Measure of Central of tendency & measures of dispersion 16 / 104 16) A parameter is a measure which is computed from a. Test statistics b. Sample data c. Raw data d. Population data 17 / 104 17) In inferential statistics, we study a. How to make decisions about mean, median, or mode b. How to estimate the sample size c. How a sample is obtained from a population d. The methods to make decisions about population based on sample results 18 / 104 18) What is the correct statement of sensitivity of a screening test: a. The proportion of patients who test positive who actually have the disease. b. The ability of the test to identify correctly those who have the disease. c. The ability of a test to indicate which individuals have the disease and which do not. d. The ability of the test to identify correctly those who do not have the disease. 19 / 104 19) In statistics, a sample mean: a. .A portion of the population b. .A portion of the sample c. All the items under investigation d. .A set of data 20 / 104 20) All statements below are correct to describe the positive predictive value of a screening test except one: a. The proportion of patients who test positive who actually have the disease. b. Likelihood of having the disease when test is positive. c. The proportion of positive test results that are true positive. d. Likelihood of not having the disease when test is negative 21 / 104 21) You asked five of your classmates about their height. On the basis of this information, you stated that the average height of all students in your university or college is 1.67 meters. This is an example of: a. Inferential Statistics b. Parameter c. Descriptive statistics d. Population 22 / 104 22) The width of a confidence interval is influenced by: a. The sample size n b. The distance between the sample mean and the population mean c. The standard error d. The sampling distribution 23 / 104 23) If a positive predictive value was 44%, it means that: a. Among those who had a positive screening new test, the probability of disease was 56%. b. Among those who had a negative screening new test, the probability of being disease-free was 56% c. Among those who had a positive screening new test, the probability of disease was 44%. d. Among those who had a negative screening new test, the probability of being disease-free was 44% 24 / 104 24) The Positive Predictive Value was 40% means that: a. The incidence of disease was 44% b. The prevalence rate is 44% c. Among those who had a positive screening new test, the probability of disease was 44%. d. The prevalence of disease was 44% 25 / 104 25) In descriptive statistics, we study: a. How to describe the probability distribution b. How to calculate the sample size in a study c. The methods for organizing, displaying and describing data d. The description of decision making process 26 / 104 26) A screening test result for cervical cancer show that PPV= 67%. It means that: a. Among those who had a positive screening new test, the probability of cervical cancer was more than 67% b. Among those who had a positive screening new test, the probability of cervical cancer was 67%. c. Among those who had a positive screening new test, the probability of cervical cancer was less than 67% d. Among those who had a positive screening new test, the probability of cervical cancer was 33% 27 / 104 27) Which branch of statistics deals with the techniques that are used to organize, and summarize and simplify data: a. Probability Statistics b. Inferential Statistics c. Descriptive Statistics d. Advanced Statistics 28 / 104 28) Which of the statements is true if a particular event has a probability of 10%? a. It is certain to happen b. It is impossible to happen c. There is a one-in-ten chance it will happen. d. It is likely to happen 29 / 104 29) Which below statement is not correct: a. .A point estimate is used to estimate the population parameter b. .A point estimate is single numberthat is an estimate of the population parameter c. .A point estimate is two numbersthat are estimate of the population parameter d. .A point estimate is the statistic computed from sample information 30 / 104 30) What is the correct statement of specificity of a screening test: a. The ability of a test to indicate which individuals have the disease and which do not. b. The proportion of patients who test positive who actually have the disease. c. The ability of the test to identify correctly those who do not have the disease. d. The ability of the test to identify correctly those who have the disease. 31 / 104 31) On the statements below which are validstatements of probability: a. The probability that this patient will die is between 101% to 200% b. The probability that this patient will die is greater than 100% c. The probability that this patient will die is less than 0% d. The probability that this patient will die is less than 10% 32 / 104 32) What is the statement of sensitivity of a diagnostic test: a. The proportion of patients who test negative who are actually free of the disease b. The ability of the test to identify correctly those who have the disease from all individuals with the disease c. The ability of the test to identify correctly those who do not have the disease from all individuals free from the disease d. The proportion of patients who test positive who actually have the disease. 33 / 104 33) We measure the sample using statistics in order to: a. To provide the reliability of the study result b. To provide the validity of the study result c. Draw inferences about the parameters of the population d. Draw conclusion about the sample size 34 / 104 34) When the new drug was clinically tested, 117 patients reported headaches and 617 did not. Based on this sample what is the probability that a new drug user will experience a headache: a. 617/117 b. 117/(117+617) c. 117/617 d. 617/(117+617) 35 / 104 35) What is the statement of negative predictive value of a diagnostic test: a. The proportion of patients who test positive who actually have the disease. b. The ability of the test to identify correctly those who have the disease from all individuals with the disease c. The ability of the test to identify correctly those who do not have the disease from all individuals free from the disease d. The proportion of patients who test negative who are actually free of the disease 36 / 104 36) If the penalty for missing a case is high (e.g., the disease is fatal and treatment exists, or disease easily spreads) the best diagnostic test is: a. use a cut-point with high specificity b. Maximize true positives c. use a cut-point with low specificity d. use a cut-point with low sensitivity 37 / 104 37) Below is the common screening test except one: a. Fasting blood cholesterol for heart disease b. Pap smear for cervical dysplasia or cervical cancer c. Rapid diagnostic test d. Fasting blood sugar for diabetes 38 / 104 38) Statistic is a numerical quantity, which is calculated from: a. Data b. Sample c. Population d. Observation 39 / 104 39) Which below statement is not correct: a. The confidence interval represents a range of values on either side of the estimate b. The narrower the confidence interval, the less precise the point estimate c. The narrower the confidence interval, the more precise the point estimate. d. Confidence interval describes the precision of the estimate 40 / 104 40) Since the population size is always larger than the sample size, then the sample statistic a. Can be smaller, larger, or equal to the population parameter b. Can never be equal to the population parameter c. Can never be smaller than the population parameter d. Can never be larger than the population parameter 41 / 104 41) A screening test result for cervical cancer show that NPV= 99%. It means that: a. Among those who had a negative screening new test, the probability of being cervical cancer-free was less than 99% b. Among those who had a negative screening new test, the probability of being cervical cancer-free was 99% c. Among those who had a negative screening new test, the probability of being cervical cancer-free was 1% d. Among those who had a negative screening new test, the probability of being cervical cancer-free was more than 99% 42 / 104 42) A negative predictive value of a test decreases as: a. The prevalence of disease in the population decreases b. The prevalence of disease in the population increases c. The incidence of disease in the population increases d. The prevalence of disease in the population is constant 43 / 104 43) The factors that determine the width of a confidence interval are except one: a. The means of sample b. The sample size, n. c. The desired level of confidence. d. The variability in the population, usually σ estimated by s. 44 / 104 44) Which of the following statements is true about the standard error of a proportion? a. It is always greater than the standard deviation b. It is a measure of the sampling variation of the observed proportion p about the true 3 (population) proportion ( c. It always lies close to 0 d. It is approximately equal to the standard deviation when the sample size is large 45 / 104 45) In statistics, a population consists of a. All people living in a country b. All subjects or objects whose characteristics are being studied c. All people living in the area under study d. All people who developing disease 46 / 104 46) Which below statement is not correct: a. .A confidence interval is a range of values within which, we believe, the true parameter don’t lies with high probability b. .A confidence interval estimate is a range of values constructed from sample data c. .A confidence interval is a range of values within which, we believe, the true parameter lies with high probability. d. The population parameter is likely to occur within a confidence interval range at a specified probability 47 / 104 47) Which of these is most likely to happen? a. Event D, which has a probability of 0.1 b. Event C, which has a probability of 0.5 c. Event B, which has a probability of 0.75 d. Event A, which has a probability of 25% 48 / 104 48) The Negative Predictive Value was 98% means that: a. The incidence of disease was 98% b. Among those who had a negative screening new test, the probability of being disease-free was 98%. c. The prevalence of disease was 98% d. The prevalence rate is 98% 49 / 104 49) The negative predictive value of a test decreases: a. The prevalence of disease decreases b. The number of population stable c. The incidence of disease increase d. Prevalence of the disease in the population increases 50 / 104 50) The primary reason for selecting a sample from a population is: a. To save time b. To draw inferences about that population c. To save money d. To provide evidence of the study result 51 / 104 51) The width of a confidence interval is influenced by: a. The distance between the sample mean and the population mean b. The population parameter. c. The sample size determination d. The desired level of confidence 52 / 104 52) Which below statement is not correct: a. Parameters are fixed values b. We rarely know parameters c. Parameters are not fixed values. d. It is often difficult to obtain measures from the entire population 53 / 104 53) The Positive Predictive Value of a test increases: a. The prevalence of disease decreases b. Prevalence of the disease in the population increases c. The number of population stable d. The incidence of disease increase 54 / 104 54) Positive Predictive Value primarily depends on (chose the incorrect answer): a. Incidence of the disease b. Sensitivity and specificity c. In general, it depends more on the specificity d. Prevalence of the disease in the population tested, 55 / 104 55) The upper bound and lower bound of confidence interval are calculated using (chose the correct answer): a. The median and the range b. The mean and the range c. The median and its standard error d. The mean and its standard error 56 / 104 56) If we want less chance of error we could calculate (chose the correct answer): a. .A 90% confidence interval b. .A 99% confidence interval c. .A 95% confidence interval d. .A 98% confidence interval 57 / 104 57) A group of 100 people are asked to state their favourite colour. 60 say blue. This experiment says that the probability of someone choosing blue is: a. 30% b. 60% c. 50% d. 40% 58 / 104 58) On the statements below which are valid statements of probability: a. .A women’s probability suffering from breast cancer in her life-time is 12 in 2 b. .A women’s probability suffering from breast cancer in her life-time is 12 in 1 c. .A women’s probability suffering from breast cancer in her life-time is 1 in 12 d. .A women’s probability suffering from breast cancer in her life-time is 12 in 3 59 / 104 59) If the variance of a data set is correctly computed with the formula using n – 1 in the denominator, which of the following is true? a. The data set is from a census b. The data set is a sample c. The data set is a population d. The data set could be either a sample or a population 60 / 104 60) Students had attended a blood donor session at the University of Health Science when a new donor arrived. Blood can be classified into 4 groups: O, A, B and AB. The table below shows the number of people in each blood group. What is the probability that the next donor belongs to blood group O? a. 3% b. 46% c. 8% d. 43% 61 / 104 61) The height of a student is 1.62 meters. This is an example of: a. Continuous data b. Qualitative data c. Categorical data d. Discrete data 62 / 104 62) If an event has a probability of 0.1 it is: a. Very unlikely to happen. b. Impossible to happen c. Very likely to happen. d. Certain to happen 63 / 104 63) What is the statement of positive predictive value of a diagnostic test: a. The ability of the test to identify correctly those who do not have the disease from all individuals free from the disease b. The proportion of patients who test positive who actually have the disease. c. The ability of the test to identify correctly those who have the disease from all individuals with the disease d. The proportion of patients who test negative who are actually free of the disease 64 / 104 64) Which answer below is not correct about the confidence interval: a. Confidence interval can be calculated by SAS b. Confidence interval cannot be calculated by hand c. Confidence interval can be calculated by Stata d. Confidence interval can be calculated by SPSS 65 / 104 65) What is the correct answer about a point estimatestatement: a. .A point estimate is a multiple numbers b. .A point estimate is a range of the sample value c. .A point estimate is a single number d. .A point estimate is always less than a population value 66 / 104 66) If a specificity of a screening test was 89%, it means that: a. The probability of the screening test correctly identifying non-diseased subjects was 89%. b. The probability of the screening test incorrectly identifying non-diseased subjects was 21%. c. The probability of the screening test correctly identifying non-diseased subjects was 21%. d. The probability of the screening test incorrectly identifying non-diseased subjects was 89%. 67 / 104 67) If we want higher chance of error we could calculate (chose the correct answer): a. .A 99% confidence interval b. .A 98% confidence interval c. .A 90% confidence interval d. .A 95% confidence interval 68 / 104 68) A confidence interval is describe (chose the correct answer): a. The validity of the estimate b. The sampling distribution. c. The precision of the estimate d. The sampling error of the estimate 69 / 104 69) What is the correct answer about a confidence interval statement: a. The narrower the confidence interval, the invalid the point estimate b. The narrower the confidence interval, the more precise the point estimate c. The narrower the confidence interval, the decreased sample size d. The narrower the confidence interval, the less precise the point estimate 70 / 104 70) A normal distribution curve is determined by the (chose the correct answer): a. Mean and sample size b. Range and standard deviation c. Range and sample size d. Mean and standard deviation 71 / 104 71) What is the correct statement of validity of a screening test: a. The ability of the test to identify correctly those who have the disease. b. The proportion of patients who test positive who actually have the disease. c. The ability of the test to identify correctly those who do not have the disease. d. The ability of a test to indicate which individuals have the disease and which do not. 72 / 104 72) What is the statement of specificity of a diagnostic test: a. The ability of the test to identify correctly those who do not have the disease from all individuals free from the disease b. The ability of the test to identify correctly those who have the disease from all individuals with the disease c. The proportion of patients who test negative who are actually free of the disease d. The proportion of patients who test positive who actually have the disease. 73 / 104 73) The meaning of reliability of a test is: a. The results of a test deferent b. The results of a test identical if repeated c. The results of a test positive d. The results of a test various 74 / 104 74) ស្ថិតិវិទ្យា (statistics) មានចែកចេញជា a. Inferential statistics & hypothesis testing b. Descriptive & inferential statistic c. Inferential statistics & standard deviation d. Descriptive statistics & estimation 75 / 104 75) On the statements below what is valid statements of probability: a. .A woman’s probability of suffering from breast cancer in her life-time is more than 1 b. .A woman’s probability of suffering from breast cancer in her life-time is 1 in 12 c. .A woman’s probability of suffering from breast cancer in her life-time is less than 0. d. .A woman’s probability of suffering from breast cancer in her life-time is 12 in 1 76 / 104 76) A positive predictive value of a test increases as: a. The prevalence of disease in the population increases b. The prevalence of disease in the population is constant c. The prevalence of disease in the population decreases d. The incidence of disease in the population increases 77 / 104 77) In descriptive statistics, we study: a. How to describe the probability distribution b. The methods for organizing, displaying, and describing data c. The prediction of disease trend d. The description of decision making process 78 / 104 78) What is the correct statement of positive predictive value (PPV) of a screening test: a. The ability of the test to identify correctly those who do not have the disease. b. The ability of a test to indicate which individuals have the disease and which do not. c. The ability of the test to identify correctly those who have the disease. d. The proportion of patients who test positive who actually have the disease. 79 / 104 79) If a sensitivity of a screening test was 80%, it means that: a. The probability of the screening test incorrectly identifying diseased subjects was 20%. b. The probability of the screening test correctly identifying diseased subjects was 20%. c. The probability of the screening test correctly identifying diseased subjects was 80%. d. The probability of the screening test incorrectly identifying diseased subjects was 80%. 80 / 104 80) What is the correct statement of diagnostic test: a. The diagnostic test is performed before a positive screening b. .A diagnostic test is used to determine the presence or absence of a disease when a subject does not shows signs or symptoms of the disease c. .A diagnostic test is not used to determine the presence or absence of a disease when a subject shows signs or symptoms of the disease d. .A diagnostic test is used to determine the presence or absence of a disease when a subject shows signs or symptoms of the disease 81 / 104 81) The width of a confidence interval will decrease when which of the following changes occur: a. The sample size n increases b. The precision of the estimate of the population mean decreases c. The sample size n decreases d. The desired level of confidence increases 82 / 104 82) What is the correct statement of screening test: a. The screening test is performed after a positive diagnostic test b. .A screening test is used to determine the presence or absence of a disease when a subject does not shows signs or symptoms of the disease c. The screening test is performed after a negative diagnostic test d. .A screening test is used to determine the presence or absence of a disease when a subject shows signs or symptoms of the disease 83 / 104 83) Reliability of a test means that: a. The results of a test or measure are changed each time it is conducted b. The results of a test or measure are not identical or closely similar each time it is conducted c. The results of a test or measure are incorrect each time it is conducted d. The results of a test or measure are identical or closely similar each time it is conducted 84 / 104 84) What is the correct interpretation of 95% confidence interval below: a. We can be 98% confident that the true value of population lies within this interval b. We can be 99% confident that the true value of population lies within this interval c. We can be 90% confident that the true value of population lies within this interval d. We can be 95% confident that the true value of population lies within this interval 85 / 104 85) Chose the incorrect statement describe the diagnostic test: a. Diagnostic tests are never perfect. b. Diagnostic tests are sometimes provide false negative result c. Diagnostic tests are always perfect. d. Diagnostic tests are sometimes provide false positive result 86 / 104 86) Confidence intervals are calculated for proportions, rates, risk ratios, odds ratios, and other epidemiologic measures: a. When the purpose to calculate test statistics b. When the purpose is to draw inferences from a sample survey or study to the larger population. c. When the purpose is to calculate sample size d. When the purpose is to test hypothesis 87 / 104 87) When data are collected in a statistical study for only a portion or subset of all elements of interest we are using a. .A parameter b. An observation c. .A sample d. .A population 88 / 104 88) The Positive Predictive Value depends on: a. The prevalence of disease b. The incidence of disease c. The number of population d. Prevalence of the disease in the population tested, 89 / 104 89) A confidence interval estimate is (chose the correct answer): a. .A standard deviation of values constructed from sample data b. .A range of values constructed from sample data c. .A median of values constructed from sample data d. .A mean of values constructed from sample data 90 / 104 90) What is the correct interpretation of 95% confidence interval below: a. In repeated sampling, 95% of the 95% CIs calculated in this manner would capture the true value of population. b. In repeated sampling, 95% of the 95% CIs calculated in this manner would not be capture the true value of population c. In repeated sampling, 95% of the 95% CIs calculated in this manner would capture the value of sample d. In repeated sampling, 95% of the 95% CIs calculated in this manner would not be capture the true value of sample 91 / 104 91) A positive predictive value depend on: a. The incidence of the disease in the population tested b. The mortality of the disease in the population tested c. The negative predictive value of the disease in the population tested d. The prevalence of the disease in the population tested 92 / 104 92) The standard error of the mean of a sample is: a. An estimate of the standard deviation of the population b. Increased as the sample size increases c. Not used to determine confidence limit d. Not based on a normal distribution 93 / 104 93) តើអ្វីខ្លះជាផ្នែករបស់ Descriptive statistics? a. Median b. Mode c. Mean d. Mode, Median & Mean 94 / 104 94) A positive predictive value depend on: a. The sensitivity of the disease in the population tested b. The negative predictive value of the disease in the population tested c. The incidence of the disease in the population tested d. The mortality of the disease in the population tested 95 / 104 95) If an event has a probability of 0.8 it is: a. Certain to happen b. Likely to happen. c. Impossible to happen d. Unlikely to happen 96 / 104 96) Population census is conducted through a. Complete enumeration b. Investigation c. Accounting d. Sample survey 97 / 104 97) All statements below are correct to describe the negative predictive value of a screening test except one: a. The proportion of negative test results that are true negative b. The proportion of patients who test negative who are actually free of the disease c. Likelihood of not having the disease when test is negative. d. The proportion of patients who test positive who actually have the disease. 98 / 104 98) A numerical value used as a summary measure for a sample, such as sample mean, is known as a a. Sample statistic b. Population parameter c. Sample parameter d. Population mean 99 / 104 99) What is the correct answer about a point estimate statement: a. .A point estimate is a true value of the study population parameter. b. .A point estimate is the statistic, computed from population information c. .A point estimate is used to estimate the sample size d. .A point estimate is the statistic, computed from sample information, 100 / 104 100) What is the correct statement of negative predictive value (NPV) of a screening test: a. The proportion of patients who test negative who are actually free of the disease b. The ability of the test to identify correctly those who do not have the disease. c. The ability of a test to indicate which individuals have the disease and which do not. d. The ability of the test to identify correctly those who have the disease. 101 / 104 101) The standard error of the mean of a sample is: a. An estimate of the standard deviation of the sample b. Based on a non-normal distribution c. Not increased as the sample size increases d. Used to determine confidence level of significant test 102 / 104 102) The director of the blood bank wants to know whether blood donors who test positive should be informed of their positive HIV status on the basis of this test. What do you need to calculate in order to help you advise the director? a. Negative predictive value b. Specificity c. Positive predictive value d. Sensitivity 103 / 104 103) What is the correct interpretation of 95% confidence interval below: a. In repeated sampling, 95% of the interval will capture the population values. b. In repeated sampling, 95% of the interval will not capture the population values. c. In repeated sampling, 95% of the interval will capture the sample values. d. In repeated sampling, 95% of the interval will not capture the sample values. 104 / 104 104) A population parameter is likely to occur (chose the correct answer): a. Within the confidence interval b. Within a standard deviation of a sample c. Within a standard deviation of a population d. Within the range values of sample Your score isThe average score is 86% Facebook 0% Restart quiz Any comments? Send feedback