Answer:
a) H1: µ < 7.5
Explanation:
From the given information:
mean = 7.5
sample size = 50
sample mean = 9.3
The main task we are to carry out is to identify the correct alternative hypothesis:
Now to do that, let's state the null and the alternative hypothesis from the given study.
The null hypothesis can be computed as:

The alternative hypothesis can be computed as:

Thus, this test hypothesis is a one-tailed test (left tailed).