You Have Collected Weekly Earnings and Age Data from a Sub-Sample

question 54

Essay

You have collected weekly earnings and age data from a sub-sample of 1,744 individuals using the Current Population Survey in a given year.
(a)Given the overall mean of $434.49 and a standard deviation of $294.67, construct a 99% confidence interval for average earnings in the entire population. State the meaning of this interval in words, rather than just in numbers. If you constructed a 90% confidence interval instead, would it be smaller or larger? What is the intuition?
(b)When dividing your sample into people 45 years and older, and younger than 45, the information shown in the table is found. $\begin{array} { | c | c | c | c | } \hline \text { Age Category } & \text { Average Earnings } \bar { Y } & \text { Standard Deviation } S _ { Y } & N \\\hline \text { Age } \geq 45 & \$ 488.87 & \$ 328.64 & 507 \\\hline \text { Age } < 45 & \$ 412.20 & \$ 276.63 & 1237 \\\hline\end{array}$ Test whether or not the difference in average earnings is statistically significant. Given your knowledge of age-earning profiles, does this result make sense?

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Definitions:

Universal Job Design

A conceptual approach to creating jobs that can be effectively and efficiently performed by a wide variety of individuals.

Job Characteristics Theory

A theory that suggests that the nature of a job itself affects employees' motivation, satisfaction, and performance, identifying five core job dimensions that impact these outcomes.

Job Rotation

A human resources strategy where employees rotate between various jobs at the same business to gain experience and skills across different roles and departments.

Cash Register

An electronic or mechanical device used in retail environments to calculate and record sales transactions, and to store cash.