Q-Mart Is Interested in Comparing Customers Who Used Its Own

Essay

Q-Mart is interested in comparing customers who used its own charge card with those who use other types of credit cards. Q-Mart would like to know if customers who use the Q-Mart card spend more money per visit, on average, than customers who use some other type of credit card. They have collected information on a random sample of 38 charge customers and the data is presented below. On average, the person using a Q-Mart card spends $192.81 per visit and customers using another type of card spend $104.47 per visit.
-(A) Given the information above, what is and for this comparison? Also, does this represent a one-tailed or a two-tailed test? Explain your answer.
​
(B) What are the degrees of freedom for the t-statistic in this calculation? Explain how you would calculate the degrees of freedom in this case.
​
(C) What is the assumption in this case that allows you to use the pooled standard deviation for this test?
​
(D) Using a 5% level of significance, is there sufficient evidence for Q-Mart to conclude that customers who use the Q-Mart card charge, on average, more than those who use another charge card? Explain your answer.
​
(E) Using a 1% level of significance, is there sufficient evidence for Q-Mart to conclude that customers who use the Q-Mart card charge, on average, more than those who use another charge card? Explain your answer.