MATH 225N Week 4 Statistics Quiz – Question and Answers (Chamberlain College of Nursing). • Course

MATH 225N Week 4 Statistics Quiz – Question and
Answers (Chamberlain College of Nursing).
 Course

 MATH 225N (MATH225)

1. What is the purpose of the Central Limit Theorem in statistics?

 A. To calculate the variance of a population.

 B. To describe the shape of the sampling distribution of the sample mean.

 C. To determine if a data set is normally distributed.

 D. To calculate the probability of an event.

Answer: B. To describe the shape of the sampling distribution of the sample mean.

Rationale: The Central Limit Theorem (CLT) states that the sampling distribution of the sample mean
will tend to be normal or nearly normal if the sample size is large enough, regardless of the shape of
the population distribution. This is key in making statistical inferences.



2. Which of the following is NOT a measure of dispersion?

 A. Variance

 B. Standard deviation

 C. Range

 D. Mean

Answer: D. Mean

Rationale: The mean is a measure of central tendency, not dispersion. Dispersion refers to how
spread out the data is, and measures of dispersion include variance, standard deviation, and range.



3. In a normal distribution, what percentage of data lies within two standard deviations from the
mean?

 A. 68%

 B. 95%

 C. 99.7%

 D. 50%

Answer: B. 95%

Rationale: According to the Empirical Rule (68-95-99.7 rule), in a normal distribution, approximately
95% of the data lies within two standard deviations from the mean.

, 4. What is the probability of drawing a red card from a standard deck of cards?

 A. 1/52

 B. 1/2

 C. 26/52

 D. 1/4

Answer: C. 26/52

Rationale: A standard deck of cards has 52 cards, half of which are red (26 red cards: 13 hearts and
13 diamonds). Therefore, the probability of drawing a red card is 26/52, or 1/2.



5. Which of the following is a correct interpretation of a p-value of 0.03 in hypothesis testing?

 A. There is a 3% chance that the null hypothesis is true.

 B. There is a 3% chance of observing the data if the null hypothesis is true.

 C. The null hypothesis should always be rejected.

 D. The result is statistically insignificant.

Answer: B. There is a 3% chance of observing the data if the null hypothesis is true.

Rationale: A p-value of 0.03 means there is a 3% chance of observing the sample data, or something
more extreme, assuming the null hypothesis is true. If the p-value is less than the significance level
(usually 0.05), the null hypothesis is rejected.



6. In a dataset, if the mean is much larger than the median, what can be inferred about the
distribution?

 A. The distribution is symmetric.

 B. The distribution is negatively skewed.

 C. The distribution is positively skewed.

 D. The distribution is normal.

Answer: C. The distribution is positively skewed.

Rationale: When the mean is larger than the median, it indicates that the distribution is positively
skewed (or right-skewed), meaning there are a few large values that pull the mean to the right.



7. Which of the following is an example of a continuous variable?

 A. Number of students in a classroom.

 B. Temperature in degrees Fahrenheit.

 C. Number of cars in a parking lot.