Will improving customer service result in higher stock prices for the companies providing the better service? "When a company's satisfaction score has improved over the prior year's results and is...

Will improving customer service result in higher stock prices for the companies providing the better service? "When a company's satisfaction score has improved over the prior year's results and is above the national average (currently ), studies show its shares have a good chance of outperforming the broad stock market in the long run." The following satisfaction scores of three companies for the 4th quarters of two previous years were obtained from the American Customer Satisfaction Index. Assume that the scores are based on a poll of  customers from each company. Because the polling has been done for several years, the standard deviation can be assumed to equal  points in each case.

Company	Year 1 Score	Year 2 Score
Rite Aid	74	75
Expedia	76	78
J.C. Penney	77	81

Extracted text: Will improving customer service result in higher stock prices for the companies providing the better service? "When a company's satisfaction score has improved over the prior year's results and is above the national average (currently 75.7), studies show its shares have a good chance of outperforming the broad stock market in the long run." The following satisfaction scores of three companies for the 4th quarters of two previous years were obtained from the American Customer Satisfaction Index. Assume that the scores are based on a poll of 66 customers from each company. Because the polling has been done for several years, the standard deviation can be assumed to equal 7 points in each case. Company Year 1 Score Year 2 Score Rite Aid 74 75 Expedia 76 78 J.C. Penney 77 81 a. For Rite Aid, is the increase in the satisfaction score from year 1 to year 2 statistically significant? Use a = .05 and null hypothesis is Ho : µ1 – µ2 <0. what="" can="" you="" conclude?="" z="" value="" (to="" 2="" decimals)="" p-value="" (to="" 4="" decimals)="" the="" difference="" is="" v="" statistically="" significant.="" b.="" can="" you="" conclude="" that="" the="" year="" 2="" score="" for="" rite="" aid="" is="" above="" the="" national="" average="" of="" 75.7?="" use="" a=".05" and="" null="" hypothesis="" is="" ho="" :="">< 75.7.="" enter="" negative="" value="" as="" negative="" number.="" z="" value="" (to="" 2="" decimals)="" p-value="" (to="" 4="" decimals)="" we="" can="" conclude="" that="" customer="" service="" has="" improved="" for="" rite="" aid.="" c.="" for="" expedia,="" is="" the="" increase="" from="" year="" 1="" to="" year="" 2="" statistically="" significant?="" use="" a=".05" and="" null="" hypothesis="" is="" ho="" :="" µi="" –="" z="" value="" (to="" 2="" decimals)="" p-value="" (to="" 4="">


Extracted text: The difference is v statistically significant. d. When conducting a hypothesis test with the values given for the standard deviation, sample size, and a, how large must the increase from Year 1 to Year 2 be for it to be statistically significant? (to 2 decimals) e. Use the result of part (d) to state whether the increase for J.C. Penney from year 1 to year 2 is statistically significant. The increase is v statistically significant.