Answer:
The sample size is 1875.
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 margin of error is:
Sampling error of 0.03.
This means that
99.74% confidence level
So , z is the value of Z that has a pvalue of , so .
25% of all adults had used the Internet for such a purpose
This means that
What is the sample size
The sample size is n. So
Simplifying by 0.03 both sides
The sample size is 1875.