Question

K.Brew sells a wide variety of outdoor equipment and clothing. The company sells both through mail order and via the internet. Random samples of sales receipts were studied for mail-order sales and internet sales, with the total purchase being recorded for each sale. A random sample of 18 sales receipts for mail-order sales results in a mean sale amount of $85.60$⁢85.60 with a standard deviation of $26.75 A random sample of 12 sales receipts for internet sales results in a mean sale amount of $98.60 with a standard deviation of $16.75 Using this data, find the 98% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases. Assume that the population variances are not equal and that the two populations are normally distributed.

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

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

3-Construct the 98% confidence interval. Round your answers to two decimal places.

Answer 1