Answer:
The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).
Explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the z-score that has a p-value of
.
In a random sample of 250 students, we found that 75 work out 4 or more times a week.
This means that

95% confidence level
So
, z is the value of Z that has a p-value of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 95% confidence interval for the proportion of students who work out 4 or more times a week is (0.2432, 0.3568).