A Major Retail Clothing Store Is Interested in Estimating the Difference

question 13

Multiple Choice

A major retail clothing store is interested in estimating the difference in mean monthly purchases by customers who use the store's in-house credit card versus using a Visa, Mastercard, or one of the other major credit cards. To do this, it has randomly selected a sample of customers who have made one or more purchases with each of the types of credit cards. The following represents the results of the sampling: Suppose that the managers wished to test whether there is a statistical difference in the mean monthly purchases by customers using the two types of credit cards, using a significance level of .05, what is the value of the test statistic assuming the standard deviations are known?

• A) t = 3.49
• B) z = 11.91
• C) z = 2.86
• D) z = 3.49

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Definitions:

Aging

refers to the process of becoming older or more mature, involving biological, psychological, and social changes over time.

Psychiatric Disorder

A mental illness diagnosed by a medical or mental health professional that significantly interferes with an individual's cognitive, emotional, or social abilities.

American Psychiatric Association

A professional organization of psychiatrists aimed at advancing the study, prevention, and treatment of mental illnesses.

Phrenologists

Pseudoscientific practitioners who believed that the shape and size of the cranium could predict personality traits, character, and mental abilities.