Question

A market analyst wants to know if the new website he designed is showing increased page views per visit and calculates the summary statistics in the table to the right. You may assume that the data come from a distribution that is Normally distributed. Complete parts a through d below.	Website 1	Website 2
	n1=80	n2=90
	y1= 6.9	y2=6.8
	s1= 3.7	s2=3.5

( , )

Find a 95% confidence interval for the mean​ difference, μ1−μ2​, in page views from the two websites.

​(Round to two decimal places as​ needed.)

Answer 1

Since, the sample sizes are large, we used standard normal distribution to find the confidence interval.

A 95% confidence level has significance level of 0.05 and critical value is,

The margin of error (E) is,

The 95% confidence interval for the mean difference (μ1 - μ2) is,

Therefore, required confidence interval is, (-0.99, 1.19)