Question

An instructor of a biology class believes the average final exam score for his biology class was more than 75. Suppose a sample of 25 was taken and the sample mean he observed was 78.48 and a standard deviation of 5 points. What is the value of the test statistic?Report your answer to 2 decimal places.

Answer 1

The value for the test statistics = 3.48

Explanation:

Given that:

population mean
`\mu` = 75

sample size n = 25

sample mean
`\overline x`= 78.48

standard deviation = 5

The value for the test statistics can be computed by using the formula:

`z = (\overline x- \mu)/((\sigma)/(√(n)))`

`z = (78.48- 75)/((5)/(√(25)))`

`z = (3.48)/((5)/(5))`

z = 3.48

The value for the test statistics = 3.48