Question

Academic tenure is when a teaching or research position is given to a professor indefinitely. By removing concerns about job security for scholars, offering tenure is thought to encourage freedom of thought, and leaves a tenured professor with the freedom to explore and hold a variety of views. One data set that was released by the Integrated Postsecondary Education Data System (IPEDS) in 2018 contained 1347 private schools, 743 of which had tenured faculty. Suppose that a prospective college student is considering whether to apply to private or public colleges. In addition to considerations about cost, graduation rates, etc., he wants to know about the quality of the education and decides to use tenure as a way of measuring this. He knows that the majority (more than 0.5) of public schools have avenues for professors to apply for tenure, and wants to test whether this is true for private schools as well. Which of the following is the correct null hypothesis in words?
A. The true proportion of private colleges in the U.S. that have tenure-track faculty is not equal to 0.5.
B. The true proportion of private colleges in the U.S. that have tenure-track faculty is 743/1347.
C. The proportion of private colleges in this sample that have tenure-track faculty is greater than 0.5 .
D. The long-run proportion of private colleges in the US, that have tenure-track faculty is 0.5.
Write the correct alternative hypothesis in notation.

Answer 1

Answer:

The correct null hypothesis in words is:

D. The long-run proportion of private colleges in the US, that have tenure-track faculty is 0.5.

$H_0: \pi = 0.5$

Step-by-step explanation:

He wants to test the claim that the proportion of private schools that have avenues for professors to apply for tenure is significantly higher than 0.5, as happen with the public schools.

Then, the alternative hypothesis is:

$H_a: \pi >0.5$  

The null hypothesis represents the opposite claim, where the proportion is not significantly higher than 0.5. Then, the null hypothesis is expressed as:

$H_0: \pi = 0.5$

The correct null hypothesis in words is:

D. The long-run proportion of private colleges in the US, that have tenure-track faculty is 0.5.