Statistics And Probability Question 338

Question: In a study of two groups, the following results were obtained:

Group Group A B Sample Size 20 25 Sample mean 22 23 Sample standard Deviation 10 12 Which of the following statements is correct?

Options:

A) Group A is less variable then Group B because Group A’s standard deviation is smaller.

B) Group A is less variable then Group B because Group A’s sample size is smaller.

C) Group A is less variable then group B because Group A’s sample mean is smaller.

D) Group A is less variable then group B because Group A’s coefficient of variation is smaller.

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Answer:

Correct Answer: D

Solution:

[d] For Group A: Coefficient of variation $ CV_{A}=\frac{S.D.}{Mean}=\frac{10}{22}=0.4545. $ For Group B: $ CV_{B}=\frac{12}{23}=0.522 $
$ \Rightarrow $ Group A is less variable.