In 1990, the Average Duration of Long-Distance Telephone Calls Originating $9.4$

question 11

Multiple Choice

In 1990, the average duration of long-distance telephone calls originating in one town was $9.4$ minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the average duration of long-distance phone calls has changed from the 1990 mean of $9.4$ minutes. The mean duration for a random sample of 50 calls originating in the town was $8.6$ minutes. Does the data provide sufficient evidence to conclude that the mean call duration, $\mu$ , is different from the 1990 mean of $9.4$ minutes? Perform the appropriate hypothesis test using a significance level of $0.01$ . Assume that $\sigma=4.8$ minutes.

• A) With a \( z \) of \( -1.2 \) there is sufficient eridence to conclude that the mean value has changed from the 1990 mean of \( 9.4 \) minutes.
• B) With a P-value of \( 0.2302 \) there is not sufficient evidence to conclude that the mean value is less than the 1990 mean of \( 9.4 \) minutes.
• C) With a P-value of \( 0.2302 \) there is sufficient evidence to conclude that the mean value is less than the 1990 mean of \( 9.4 \) minutes.
• D) With a \( z \) of \( -1.2 \) there is not sufficient evidence to conclude that the mean value has changed from the 1990 mean of \( 9.4 \) minutes.

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Definitions:

Exempting Interest

The act of not subjecting interest earnings to taxation under certain conditions.

Loanable Funds

This term refers to the funds available for borrowing in the economy, which includes savings and any capital available for lending to others for investment.

Taxation

The practice of a government collecting revenues from individuals and businesses to fund public services and infrastructure.

Loanable Funds

A marketplace where individuals who save provide capital for those in need of loans.