In a random sample of 86 athletes participating in the 2012 Summer Olympics, 63 were found to have sponsorship by private companies. Based on this sample, conduct a hypothesis test to see if there evidence to support the claim that the true proportion (among all athletes participating in the 2012 Summer Olympics) of those with private company sponsorship is greater than 70%. Which distribution is used to compute the p‐value, and what range does the p‐value lie in?
Among the answers I had confusion between the following options
a. Z distribution, p < 0.5 b. t distribution, p < 0.5
I believe that the statistic that needs to be used is the t stat, since we have a sample of the overall population and we are deriving the population sd from the sample sd. But the official answer stated is that a Z distribution is supposed to be used.
Can anyone please weigh in?