Statistics students surveyed 135 students at Tallahassee Community College. From their data we are 95% confident that between 44.7% and 61.9% of all TCC students are female. The students realize that this interval contains a large margin of error. What can they do to make a narrower interval? Group of answer choices

a. Survey more students.

b. Use a 99% confidence level.

c. Survey more students and use a 99% confidence interval.

d. None of the other choices.

a. Survey more students.

Step-by-step 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 zscore that has a pvalue of .

The higher the confidene level, the higher the value of z is.

The margin of error is given by:

The smaller the margin of error, the narrower the interval is.

What can they do to make a narrower interval?

As we saw from the equation above, the margin of error decreases as the sample size increases.

So the correct answer is:

a. Survey more students.