test statistic question

Question

claim: The mean pulse rate​ (in beats per​ minute) of adult males is equal to

69bpm. For a random sample of

165 adult​ males, the mean pulse rate is

70.1bpm and the standard deviation is

11.1bpm. Find the value of the test statistic.

Answer 1

Since we don't know the population standard deviation, we will be computing the t-statistic for a single mean:

t-statistic = (sample mean - population mean)/standard error of sample mean

The sample mean is 70.1 bpm

The population mean is 69 bpm

The standard error of the sample mean = sample standard deviation / square root (sample size) =

11.1 / sqrt (165) = 0.864

So the t-statistic = (70.1 - 69)/0.864 = 1.273.