Question

A telephone service representative believes that the proportion of customers completely satisfied with their local telephone service is different between the West and the Northeast. The representative's belief is based on the results of a survey. The survey included a random sample of 1280 western residents and 1380 northeastern residents. 36% of the western residents and 50% of the northeastern residents reported that they were completely satisfied with their local telephone service. Find the 98% confidence interval for the difference in two proportions.

Step 1 of 3:

Find the point estimate that should be used in constructing the confidence interval

Step 2 of 3:

Find the margin of error. Round your answer to six decimal places.

Step 3 of 3:

Construct the 98% confidence interval. Round your answers to three decimal places

Consider the value of t such that 0.05 of the area under the curve is to the right of t.

Step 2 of 2:

Assuming the degrees of freedom equals 29 determine the t value. Round your answer to three decimal places

Answer 1

Step 1 of 3:

Find the point estimate that should be used in constructing the confidence interval: -0.14

Step 2 of 3:

Find the margin of error. 0.044276

Step 3 of 3:

Construct the 98% confidence interval. (-0.184, -0.096)