A recent study by the Center for Disease Control claims that a new super-contagious virus will impact a population in which it is found if left unchecked. A recent occurrence of this virus happened on a very isolated island nation with over 30,000 inhabitants. In randomly testing 400 residents of this island after the virus outbreak, a research team found 330 tested positive for having been infected by the virus.
What was the sample's proportion measure of those having been infected by the virus? That is, determine the sample measure designated as p-hat.
Is the above information sufficient for you to be certain that the percentage of all in a population who contracted the virus is the same as the value computed in part A above? Why or why not?
The CDC claims that this virus tends to impact over 80% of any population in which it is found and left unchecked. The research wishes to use the island nation results to test the CDC claim. In establishing a statistical hypothesis testing of this situation, give the required null and alternative hypotheses for a test of the claim made by the CDC.
H0:
H1:
Based on your answer in part C, should you use a right-tailed, a left-tailed, or a two-tailed test? Briefly explain how one determines which of the three possibilities is to be used.