ANSWERS LATEST 2026
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 - ANSWER-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 - ANSWER-
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 - ANSWER-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 - ANSWER-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 - ANSWER-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 - ANSWER-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 -
ANSWER-B) The sample mean is approximately normal
The Central Limit Theorem states that if the sample size is large enough, the
distribution of the
sample means can be approximated by a normal distribution, even if the original
population is not
normally distributed. In other words, the distribution of the sample means
approaches a normal distribution as the sample size increases
Assume that a researcher has measured weight in a sample of 100 overweight
adults before and after a diet and exercise program conducted at the local
health department's weekly Eat Health - Be Fit community program.
To determine whether the mean weight decreased six weeks after the exercise
program compared to the initial baseline measures, the researcher should:
A) Compute the correlation coefficient, r, and determine the association
between being overweight and the community program
B) Conduct a t-test for independent samples
C) Conduct a t-test for dependent samples
D) Conduct a chi-square test for association