A Credit Union Took a Random Sample of 400 Accounts

question 59

Multiple Choice

A credit union took a random sample of 400 accounts and obtained the following 90% confidence interval for the mean checking account balance at the institution: $2185 < μ(balance) < $3846.

• A)We are 90% confident that the mean checking account balance at this credit union is between $2185 and $3846,based on this sample.
• B)We are 90% sure that the mean balance for checking accounts in the sample was between $2185 and $3846.
• C)If we took random samples of checking accounts at this credit union,about nine out of ten of them would produce this confidence interval.
• D)About 9 out of 10 people have a checking account balance between $2185 and $3846.
• E)We are 90% confident that the mean checking account balance in the U.S.is between $2185 and $3846.

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Definitions:

Equilibrium

When aggregate demand equals aggregate supply.

MC = MR

A principle in economics stating that profit maximization occurs when a firm's marginal cost (MC) equals its marginal revenue (MR).

Marginal Revenue

The additional income gained from selling one more unit of a good or service.

Marginal Revenue

The extra revenue earned by selling an additional unit of a product or service.