TABLE 10-14
a Problem with a Telephone Line $$\text { t-Test: Two- Sample Assuming Unequal Variances }$$

question 113

Essay

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 twodifferent offices of a telephone company and the time toclear these problems (in minutes) from the customers'lines are collected. Belowis the Excel output to see whether there is evidence of a difference in the mean waitingtime between the two offices assuming that the population variances in the two offices are not equal.
$$\text { t-Test: Two- Sample Assuming Unequal Variances }$$
$$\begin{array} { l r r } & \text { Office 1 } & \text { Office 2 } \\\hline \text { Mean } & 2214 & 2.0115 \\\text { Variance } & 2.951657 & 3.57855 \\\text { Observations } & 20 & 20 \\\text { Hypothesized Mean Difference } & 0 & \\\mathrm { df } & 38 & \\\mathrm { t } \text { Stat } & 0.354386 & \\\mathrm { P } ( \mathrm { T } < = \mathrm { t } ) \text { one- tail } & 0.362504 & \\\mathrm { t } \text { Critical one- tail } & 1.685953 & \\\mathrm { P } ( \mathrm { T } < = \mathrm { t } ) \text { two- tail } & 0.725009 & \\\mathrm { t } \text { Critical two-tail } & 2.024394 & \\\hline\end{array}$$
-Referring to Table 10-14, what is the largest level of significance at which a test on a difference in the variability of the waiting time between the two offices will not be rejected?

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Definitions:

Longitudinal Design

A research design that involves repeated observations or measurements of the same variables over extended periods of time.

Violent Television

Pertains to TV programs that depict scenes of physical force intended to hurt or kill beings or cause destruction.

Aggressive Acts

Behaviors intended to harm or injure another being who is motivated to avoid such treatment.

Randomly Assigns

a method used in experiments where participants are assigned to different groups without any specific order, reducing bias.