Exhibit 9-7
A random sample of 16 statistics examinations from a large population was taken. The average score in the sample was 78.6 with a variance of 64. We are interested in determining whether the average grade of the population is significantly more than 75. Assume the distribution of the population of grades is normal.
-Refer to Exhibit 9-7. The test statistic is
A)0.45
B)1.80
C)3.6
D)8

Question

Quizplus · Accepted Answer

The test statistic for a one-sample t-test is calculated as (sample mean - hypothesized population mean) / (standard deviation / square root of sample size).

In this case: 
sample mean = 78.6 
hypothesized population mean = 75 
standard deviation = square root of variance = square root of 64 = 8 
sample size = 16

So, the test statistic is (78.6 - 75) / (8 / sqrt(16)) = 1.80.

Looking at the answer choices, the closest one is B.

Exhibit 9-7 A Random Sample of 16 Statistics Examinations from a Large