A survey was conducted by an independent price-checking company to check an advertiser's claim that it had lower prices than its competitors. The average weekly total, based on the prices of approximately 95 items, is given for this chain and for its competitor recorded during four consecutive weeks in a particular month. Week Advertiser ($) Competitor ($) 1 254.27 255.93 2 240.72 255.65 3 231.91 255.12 4 234.15 261.28
a. Is there a significant difference in the average prices for these two difference supermarket chains?b. What is the approximate p-value for the test conducted in part a?c. Construct a 99% confidence interval for the difference in the average prices for the two supermarket chains. Interpret this interval.