You are interested in estimating the the mean age of the citizens living in your community. In order to do this, you plan on constructing a confidence interval; however, you are not sure how many citizens should be included in the sample. If you want your sample estimate to be within 4 years of the actual mean with a confidence level of 95%, how many citizens should be included in your sample? Assume that the standard deviation of the ages of all the citizens in this community is 25 years.

The number of citizens that should be included in the sample is 151.

Step-by-step explanation:

The (1 - α)% confidence interval for population mean is:

The margin of error for this interval is:

The information provided is:

Confidence level = 95%

α = 5%

Compute the critical value of z for α = 5% as follows:

*Use a z-table.

Compute the sample size required as follows:

Thus, the number of citizens that should be included in the sample is 151.

the answer is 375 miles

step-by-step explanation:

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads