A national health study reported that the proportion of students with elevated blood pressure is 0.15. The principal of a local high school believes that the proportion of students in the school with elevated blood pressure is greater than 0.15. If a large random sample is used, which of the following is the most appropriate test to investigate the principal's belief?

1. A z-test for a proportion2. A z-test for the difference between two proportions3. A t-test for a mean4. A matched-pairs t-test

1. A z-test for a proportion

Step-by-step explanation:

We are interested in testing whether the proportion of students with elevated blood pressure is greater than 0.15 or not.

So, we are given a specific population proportion 0.15 and we have to test it.

Thus, the null and alternative hypothesis in this case will be

Null hypothesis : p=0.15

Alternative hypothesis: p>0.15

So, it corresponds to testing of one proportion which can be tested using a z-test for one proportion.

Hence, the appropriate test for the given scenario is z-test for a proportion.