A Random Sample of 15 Telephone Calls in an Office

question 17

Short Answer

A random sample of 15 telephone calls in an office showed the duration of each call and whether it was a local or a long distance call.
$\begin{array}{ccc}&\text { Duration }\\\text { Call Number } & \text { In Minution } &\text { Type of Call }\\1 & 2 & \text { local } \\2 & 12 & \text { long distance } \\3 & 10 & \text { local } \\4 & 3 & \text { local } \\5 & 5 & \text { long distance } \\6 & 6 & \text { local } \\7 & 3 & \text { local } \\8 & 5 & \text { local } \\9 & 8 & \text { local } \\10 & 4 & \text { local } \\11 & 5 & \text { local } \\12 & 4 & \text { local } \\13 & 5 & \text { local } \\14 & 4 & \text { local } \\15 & 9 & \text { long distance }\end{array}$
a. What is the point estimate for the average duration of all calls?
b. What is the point estimate for the standard deviation of the population?
c. What is the point estimate for the proportion of all calls that were long distance?

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Definitions:

Tax Rate

The percentage at which an individual or corporation is taxed by the government on income or profits.

Net Operating Loss Carryforward

A tax provision that allows businesses to use a net operating loss in one year to offset taxable income in future years.

Business Acquisition

The act of acquiring control over another company either by purchasing its shares, assets, or both, often aiming to expand operations or enter new markets.

Tax Rate

The percentage at which income or profits are taxed by the government.