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.

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Definitions:

Mormons

Members of The Church of Jesus Christ of Latter-day Saints, a religious group founded in the United States in the early 19th century.

Theocratic Hierarchy

A system of governance where religious leaders hold the highest authority, and the state's legal and moral codes are based on religious laws.

Protestant Christians

Followers of the branches of Christianity that originated from the Reformation in the 16th century, which protested against certain practices of the Catholic Church.

Mormons

Members of the Church of Jesus Christ of Latter-day Saints, a Christian religious group founded in the early 19th century in the United States by Joseph Smith.