TABLE 10-14
a Problem with a Telephone Line That Prevents

question 129

Multiple Choice

TABLE 10-14
A problem with a telephone line that prevents a customer from receiving or making calls is disconcerting to both the customer and the telephone company. The data on samples of 20 problems reported to two different offices of a telephone company and the time to clear these problems (in minutes) from the customers' lines are collected. Below is the Excel output to see whether there is evidence of a difference in the mean waiting time between the two offices assuming that the population variances in the two offices are not equal.
$$\begin{array}{l}\text { t- Test: Two- Sample Assuming Unequal Variances }\\\begin{array} { l r r } \hline & \text { Office 1 } & \text { Office 2 } \\\hline \text { Mean } & 2214 & 2.0115 \\\text { Variance } & 2.951657 & 3.57855 \\\text { Observations } & 20 & 20 \\\text { Hypothesized Mean Difference } & 0 & \\\mathrm { df } & 38 & \\\mathrm { t } \text { Stat } & 0.354386 & \\\mathrm { P } ( \mathrm { T } < = \mathrm { t } ) \text { one- tail } & 0.362504 & \\\mathrm { t } \text { Critical one- tail } & 1.685953 & \\\mathrm { P } ( \mathrm { T } < = \mathrm { t } ) \text { two- tail } & 0.725009 & \\\mathrm { t } \text { Critical two- tail } & 2.024394 &\end{array}\end{array}$$
-Referring to Table 10-14, what assumptions are necessary for testing if there is evidence of a difference in the variability of the waiting time between the two offices to be valid?

• A) Both samples are random and independent.
• B) Both sampled populations are normally distributed.
• C) Neither A nor B is necessary.
• D) Both A and B are necessary.

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Definitions:

Consumption And Investment

Components of an economy where consumption refers to the use of goods and services for immediate satisfaction, and investment involves spending on capital goods to yield future returns.

Production Possibilities Curve

A graphical representation showing the maximum combinations of goods or services that can be produced with a fixed amount of resources.

Operating Inefficiently

Conducting business in a manner that does not maximize output or profits relative to input and resources.

Technological Advance

The development and application of innovative tools, machines, systems, and methods to improve processes, productivity, and efficiency.