Q-Mart is interested in comparing customers who use 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 cards. They have collected information on a random sample of 38 charge customers as shown 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) Using a t - value of 2.0281, calculate a 95% confidence interval for the difference between the average Q-Mart charge and the average charge on another type of credit card. (
B) What are the degrees of freedom for the t - multiple 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 confidence interval? (
D) Would you conclude that there is a significant difference between the two types of customers in this case? Explain.

Question

Q-Mart is interested in comparing customers who use 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 cards. They have collected information on a random sample of 38 charge customers as shown 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) Using a t - value of 2.0281, calculate a 95% confidence interval for the difference between the average Q-Mart charge and the average charge on another type of credit card. (
B) What are the degrees of freedom for the t - multiple 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 confidence interval? (
D) Would you conclude that there is a significant difference between the two types of customers in this case? Explain.

Quizplus · Accepted Answer

The Answer of Q-Mart is interested in comparing customers who use 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 cards. They have collected information on a random sample of 38 charge customers as shown 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) Using a t - value of 2.0281, calculate a 95% confidence interval for the difference between the average Q-Mart charge and the average charge on another type of credit card. (
B) What are the degrees of freedom for the t - multiple 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 confidence interval? (
D) Would you conclude that there is a significant difference between the two types of customers in this case? Explain.

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