Answer:
The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is (0.46, 0.58). This means that we are 99% sure that the true proportion of all U.S. adult Twitter users who get some news on Twitter is between these two values.
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 z-score that has a p-value of .
A poll found that 52% of U.S. adult Twitter users get at least some news on Twitter. The standard error for this estimate was 2.4%
This means that:
99% 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 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is (0.46, 0.58). This means that we are 99% sure that the true proportion of all U.S. adult Twitter users who get some news on Twitter is between these two values.