CPH Exam Practice Questions and
Answers 100% Pass
The lengths of stay for six patients were 0, 0, 1, 2, 2, and 16 days. Which is (are) the best
measure(s) to summarize these data?
A) Mean
B) Median
C) Median and SD
D) Mean and SD
E) Median and Range ✔✔E) Median and Range
An epidemiologist attempts to predict the weight of an elderly person from demispan. She
randomly chooses 70 elderly subjects in a particular geographic area and records their weight
and demispan measurements in the form of (x i , y i ) for i = 1...70. Given that the value of the
Pearson correlation coefficient is zero, what can be deduced?
1) There is no relation between weight and demispan
B) There is an almost perfect relationship between weight and demispan
C) There could be some nonlinear relationship between weight and demispan
,D) There is a strong negative relationship between weight and demispan
E) All pairs of values of weight and demispan are practically identical ✔✔C) There could be
some nonlinear relationship between weight and demispan
Which of the following statistical tests is NOT considered a nonparametric test?
A) Kruskal-Wallis Test
B) Wilcoxon's rank-sum test
C) Tukey's test
D) Mann-Whitney test ✔✔C) Tukey's test
A researcher is designing a new questionnaire to examine patient stress levels on a scale of 0 to
5. What type of outcome variable is being collected?
A) Ratio
B) Nominal
C) Interval
D) Ordinal
,E) Binary ✔✔B) Ordinal
In simple linear regression, what is a method of determining the slope and intercept of the best-
fitting line?
A) Least squares
B) R-square
C) Minimum error
D) Least Error
E) Regression ✔✔A) Least Squares
The sensitivity of a particular screening test for a disease is 95%, and the specificity is 90%.
Which of the following statements is most correct?
(A) Of 100 people sampled from a population with the disease, the test will correctly detect 95
individuals as positive for the disease
(B) Of 100 people sampled from a population with the disease, the test will correctly detect 90
individuals
(C) If a person tests positive, the probability of having the disease is 0.95
, (D) If a person has the disease, there is a 5% chance that the test will be negative
(E) If a person does not have the disease, there is a 5% chance that the test will be positive
✔✔A) Of 100 people samples from a population with the disease, the test will correctly detect
95 individuals as positive for the disease.
Sensitivity is the proportion of truly diseased people in the screened population who are
identified as diseased by the screening test. It is a measure of the probability of correctly
diagnosing a case or the probability that any given case will be identified by the test (e.g., true
positives). Specificity is the proportion of truly non-diseased people who are so identified by the
screening test. It is a measure of the probability of correctly identifying a nondiseased person
with the screening test (e.g., true negatives).
The Central Limit Theorem states that:
A) The sample mean is unbiased
B) The sample mean is approximately normal
C) The parent population of the sample distribution is normally distributed
D) The sample SD is approximately normal
E) Both statements A) and C) can be deduced from the Central Limit Theorem ✔✔B) The
sample mean is approximately normal
Answers 100% Pass
The lengths of stay for six patients were 0, 0, 1, 2, 2, and 16 days. Which is (are) the best
measure(s) to summarize these data?
A) Mean
B) Median
C) Median and SD
D) Mean and SD
E) Median and Range ✔✔E) Median and Range
An epidemiologist attempts to predict the weight of an elderly person from demispan. She
randomly chooses 70 elderly subjects in a particular geographic area and records their weight
and demispan measurements in the form of (x i , y i ) for i = 1...70. Given that the value of the
Pearson correlation coefficient is zero, what can be deduced?
1) There is no relation between weight and demispan
B) There is an almost perfect relationship between weight and demispan
C) There could be some nonlinear relationship between weight and demispan
,D) There is a strong negative relationship between weight and demispan
E) All pairs of values of weight and demispan are practically identical ✔✔C) There could be
some nonlinear relationship between weight and demispan
Which of the following statistical tests is NOT considered a nonparametric test?
A) Kruskal-Wallis Test
B) Wilcoxon's rank-sum test
C) Tukey's test
D) Mann-Whitney test ✔✔C) Tukey's test
A researcher is designing a new questionnaire to examine patient stress levels on a scale of 0 to
5. What type of outcome variable is being collected?
A) Ratio
B) Nominal
C) Interval
D) Ordinal
,E) Binary ✔✔B) Ordinal
In simple linear regression, what is a method of determining the slope and intercept of the best-
fitting line?
A) Least squares
B) R-square
C) Minimum error
D) Least Error
E) Regression ✔✔A) Least Squares
The sensitivity of a particular screening test for a disease is 95%, and the specificity is 90%.
Which of the following statements is most correct?
(A) Of 100 people sampled from a population with the disease, the test will correctly detect 95
individuals as positive for the disease
(B) Of 100 people sampled from a population with the disease, the test will correctly detect 90
individuals
(C) If a person tests positive, the probability of having the disease is 0.95
, (D) If a person has the disease, there is a 5% chance that the test will be negative
(E) If a person does not have the disease, there is a 5% chance that the test will be positive
✔✔A) Of 100 people samples from a population with the disease, the test will correctly detect
95 individuals as positive for the disease.
Sensitivity is the proportion of truly diseased people in the screened population who are
identified as diseased by the screening test. It is a measure of the probability of correctly
diagnosing a case or the probability that any given case will be identified by the test (e.g., true
positives). Specificity is the proportion of truly non-diseased people who are so identified by the
screening test. It is a measure of the probability of correctly identifying a nondiseased person
with the screening test (e.g., true negatives).
The Central Limit Theorem states that:
A) The sample mean is unbiased
B) The sample mean is approximately normal
C) The parent population of the sample distribution is normally distributed
D) The sample SD is approximately normal
E) Both statements A) and C) can be deduced from the Central Limit Theorem ✔✔B) The
sample mean is approximately normal
