The claim is that for the population of adult males, the mean platelet count is μ>217. The sample size is n=50 and the test
statistic is t=1.421. I know the answer is 0.081 but I don't understand how to get that answer. Can someone please explain how to find a p-value using the test statistic either manually or with a calculator?
To find the p-value manually, use a t-score table. Find the row corresponding to 49 degrees of freedom. Then find the α column that corresponds to a t-score of 1.421. You'll find it's between α = 0.10 (t = 1.299) and α = 0.05 (t = 1.677). Interpolating, we get an approximate p-value of 0.084. For a more accurate answer, you'll need to use a calculator.