Use the following information for questions:
Exam scores for a large introductory statistics class follow an approximate normal distribution with an average score of 56 and a standard deviation of 5. The average exam score in your lab was 59.5. The 20 students in your lab sections will be considered a random sample of all students who take this class.
-What is the standard deviation of the distribution of the average exam score of the 20 students in your lab section?
A) 0.25
B) 1.12
C) 1.25
D) 5

Question

Use the following information for questions:
 Exam scores for a large introductory statistics class follow an approximate normal distribution with an average score of 56 and a standard deviation of 5. The average exam score in your lab was 59.5. The 20 students in your lab sections will be considered a random sample of all students who take this class.
-What is the standard deviation of the distribution of the average exam score of the 20 students in your lab section?
A) 0.25
B) 1.12
C) 1.25
D) 5

Quizplus · Accepted Answer

The standard deviation of the distribution of the average exam score ($\sigma_{\bar{x}}$) is found using the formula $\sigma_{\bar{x}} = \frac{\sigma}{\sqrt{n}}$, where $\sigma$ is the population standard deviation and $n$ is the sample size. Here, $\sigma = 5$ and $n = 20$, so $\sigma_{\bar{x}} = \frac{5}{\sqrt{20}} \approx 1.12$.

Use the Following Information for Questions