You are given a sample of 106 body temperatures having a mean of 98.2 F and a standard deviation of 0.62 F. You are asked to test the hypothesis that the population mean body temperature is 98.6 F using a 0.05 significance level. What value should you use for the test statistic?

Question

You are given a sample of 106 body temperatures having a mean of 98.2 F and a standard deviation of  0.62 F. You are asked to test the hypothesis that the population mean body temperature is 98.6 F using a 0.05 significance level.  What value should you use for the test statistic? 
 The answer is -6.64 but I'm confused as to how it was found.  Please help. I'm studying for a final.

PsyDAG · Answer

This is what I would do.

Z = (score-mean)/SEm

SEm = SD/√n

P ≤ .05

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score. How does it compare?