Exam | 200 Practice Questions & Detailed Answers
1–200 Practice Questions with Answers & Rationales
1. A healthcare researcher is analyzing the lengths of hospital stays (in days) for a sample of patients.
The data is found to be positively skewed. Which measure of central tendency is MOST appropriate to
accurately represent the typical length of stay?
A. Mean
B. Median
C. Mode
D. Range
Answer: B. Median
Rationale: For a positively skewed distribution, the mean is pulled toward the higher values (the tail),
making it an inaccurate representation of the center for most patients. The median is the 50th
percentile and is resistant to the influence of outliers and skew, thus providing the most accurate
measure of a typical value.
2. A nurse notes that the average heart rate of 15 patients is 72 beats per minute with a standard
deviation of 4. If the distribution is normal, approximately what percentage of these patients have a
heart rate between 68 and 76 beats per minute?
A. 50%
B. 68%
C. 95%
D. 99.7%
,Answer: B. 68%
Rationale: The values 68 and 76 represent one standard deviation below (72 − 4 = 68) and one standard
deviation above (72 + 4 = 76) the mean. According to the Empirical Rule for a normal distribution,
approximately 68% of the data falls within ±1 standard deviation of the mean.
3. A researcher is studying the relationship between a patient's age and their blood pressure. The
researcher wants to predict blood pressure based on age. What type of statistical test is most
appropriate for this analysis?
A. Chisquare test
B. Independent ttest
C. Pearson correlation coefficient
D. Simple linear regression
Answer: D. Simple linear regression
Rationale: Simple linear regression is used to model the relationship between two continuous variables
and to predict the value of a dependent variable (blood pressure) based on the value of an independent
variable (age).
4. A clinical trial is testing a new drug. The null hypothesis states that the drug has no effect. The trial
results show a pvalue of 0.03. What is the correct interpretation of this pvalue, assuming a significance
level of 0.05?
A. There is a 3% chance that the null hypothesis is true.
B. There is a 97% chance that the drug is effective.
,C. The probability of observing the trial results, or more extreme results, given that the null hypothesis is
true, is 3%.
D. The probability of a Type II error is 3%.
Answer: C. The probability of observing the trial results, or more extreme results, given that the null
hypothesis is true, is 3%.
Rationale: A pvalue is the probability of obtaining results at least as extreme as those observed,
assuming the null hypothesis is true. It is not the probability that the null hypothesis is true or false.
5. Which level of measurement classifies blood type (A, B, AB, O)?
A. Interval
B. Ordinal
C. Nominal
D. Ratio
Answer: C. Nominal
Rationale: Nominal data are categories with no inherent order, such as blood types.
6. The mean is best described as the:
A. Middle value
B. Arithmetic average
C. Most frequent value
, D. Range of values
Answer: B. Arithmetic average
Rationale: The mean is calculated by summing all values and dividing by the number of values. It is the
arithmetic average.
7. What is the value of x in the equation 2x + 3 = 13?
A. 3
B. 5
C. 7
D. 10
Answer: B. 5
Rationale: Subtract 3 from both sides: 2x = 10. Divide by 2: x = 5.
8. Which scale of measurement is being used when a nurse records a patient's temperature in degrees
Fahrenheit?
A. Nominal
B. Ordinal
C. Interval
D. Ratio