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

question 75

Essay

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.

---

Definitions:

Latane and Darley

Scientists who introduced the concept of diffusion of responsibility, explaining why people are less likely to take action or feel a sense of urgency in the presence of a group.

Bystander Intervention

The act of stepping in to help when witnessing a problematic or emergency situation, when others might not.

Cognitive Model

A framework used in psychology that explains how thoughts influence behaviors and emotions, emphasizing the role of mental processes.

Perspective Taking

The cognitive capacity to consider the world from another individual's viewpoint, enhancing empathy and understanding in interpersonal interactions.