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

question 152

Short Answer

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.
$$\text { t-Test: Two- Sample Assuming Unequal Variances }$$
$$\begin{array} { l r r } & \text { Office 1 } & \text { Office 2 } \\\hline \text { Mean } & 2214 & 2.0115 \\\text { Variance } & 2.951657 & 3.57855 \\\text { Observations } & 20 & 20 \\\text { Hypothesized Mean Difference } & 0 & \\\mathrm { df } & 38 & \\\mathrm { t } \text { Stat } & 0.354386 & \\\mathrm { P } ( \mathrm { T } < = \mathrm { t } ) \text { one- tail } & 0.362504 & \\\mathrm { t } \text { Critical one- tail } & 1.685953 & \\\mathrm { P } ( \mathrm { T } < = \mathrm { t } ) \text { two- tail } & 0.725009 & \\\mathrm { t } \text { Critical two-tail } & 2.024394 & \\\hline\end{array}$$

-Referring to Table 10-13, construct a 95% confidence interval estimate of the difference in proportion between the Kohler and Russell disks that are defective.

---

Definitions:

Functional Departmentation

The process of organizing an organization's structure based on specialized functions or tasks such as marketing, finance, or operations.

Coordination

The method of coordinating individuals or teams to ensure they collaborate effectively and efficiently.

Functional Departmentation

The process of grouping together jobs and tasks into departments based on similarity in functions, such as marketing or finance.

Chemists

Professionals who study chemicals and their interactions, often involved in developing new substances and analyzing compounds.