Question

Given two dependent random samples with the following results:

Population 1	41	39	47	18	39	21	34
Population 2	30	37	45	22	24	31	45

Use this data to find the 80% confidence interval for the true difference between the population means. Assume that both populations are normally distributed.

Step 1 of 4:

Find the point estimate for the population mean of the paired differences. Let x1 be the value from Population 1 and x2 be the value from Population 2 and use the formula d=x2−x1  to calculate the paired differences. Round your answer to one decimal place.

Use this data to find the 80% confidence interval for the true difference between the population means. Assume that both populations are normally distributed.

Step 2 of 4:

Calculate the sample standard deviation of the paired differences. Round your answer to six decimal places.

Step 3 of 4:

Calculate the margin of error to be used in constructing the confidence interval. Round your answer to six decimal places.

Step 4 of 4:

Construct the 80% confidence interval. Round your answers to one decimal place.

Answer 1

step 1:

point estimate for the population mean of the paired differences = -0.7

step 2:

Std deviaiton SD=√(Σd2-(Σd)2/n)/(n-1) =

9.894684

Step 3 of 4:

margin of error =5.385368

Step 4 of 4:

lower confidence limit                     =		-6.1
upper confidence limit                    =		4.7