Preliminary Data Analyses Indicate That You Can Reasonably Consider the Assumptions

question 44

Essay

Preliminary data analyses indicate that you can reasonably consider the assumptions for using the Mann-Whitney testsatisfied. Assume that the null hypothesis is $\mathrm { H } _ { 0 } : \mu _ { 1 } = \mu _ { 2 }$ . Use the Mann-Whitney test to carry out the requiredhypothesis test.
-A researcher was interested in comparing the salaries of female and male employees at a particular company. Independent simple random samples of 8 female employees and 9 male employees yielded the following weekly salaries (in dollars). $$\begin{array} { r | r } \text { Female } & \text { Male } \\ \hline 495 & 480 \\ 660 & 605 \\ 914 & 1250 \\ 743 & 722 \\ 520 & 1150 \\ 760 & 518 \\ 1005 & 1540 \\ 556 & 750 \\ & 530 \end{array}$$ At the 5% significance level, do the data provide sufficient evidence to conclude that at this company the mean salary of female employees is lower than the mean salary of male employees?

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Definitions:

Treadle Valve

A foot-operated valve that controls the flow of air in a pneumatic system, often used in braking systems of heavy vehicles.

Inversion Valve

A normally open air brake valve used for emergency applications of tractor brakes for a one-time stop during a total system failure. Hold-off air is dumped in relation to application pressure so that spring chamber force can effect emergency service braking. Incorporated in some modulating valves.

Tractor Protection Valve

A safety valve in commercial vehicles that prevents air loss in the tractor in the event of a trailer breakaway or air line failure.

FMVSS-121 Compliant

FMVSS-121 compliant means adhering to the Federal Motor Vehicle Safety Standard 121, relating to air brake systems in heavy vehicles.