The claim is that the IQ scores of statistics professors are normally distributed, with a mean greater than 133. A sample of 28 professors had a mean IQ score of 138 with a standard deviation of 6. Find the value of the test statistic

The value of the test statistic is 4.41

Step-by-step explanation:

Our test statistic is:

In which X is the mean of the sample, is the value of the claim, is the standard deviation and n is the size of the sample.

In this problem, we have that:

So

The value of the test statistic is 4.41