A poll conducted in 2013 found that 55% of U. S. adult Twitter users get at least some news on Twitter (Pew, 2013). The standard error for this estimate was 2.2%, and a normal distribution may be used to model the sample proportion. Construct a 99% confidence interval for the fraction of U. S. adult Twitter users who get some news on Twitter, and interpret the confidence interval in context. (please round all percentages to 2 decimal places)

The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.

Step-by-step explanation:

Confidence interval:

A confidence interval has the following format:

In which M is the sample mean, z is related to the confidence level and s is the standard error.

55% of U.S. adult Twitter users get at least some news on Twitter (Pew, 2013). The standard error for this estimate was 2.2%.

This means that

99% confidence level

So , z is the value of Z that has a pvalue of , so .

Lower bound of the interval:

Upper bound:

The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.

step-by-step explanation:

well if you round, things become much more simple. round 5.95 to 6, 4.25 to 4, and 1.05 to 1. now, add 6+4+1 and that would equal 11. so the items together would equal to about $11.