An Industrial Psychologist Is Investigating the Effects of Work Environment

An industrial psychologist is investigating the effects of work environment on employee attitudes. A group of 20 recently hired sales trainees were randomly assigned to one of four different "home rooms"- five trainees per room. Each room is identical except for wall color. The four colors used were light green, light blue, gray, and red. The psychologist wants to know whether room color has an effect on attitude, and, if so, wants to compare the mean attitudes of the trainees assigned to the four room colors. At the end of the training program, the attitude of each trainee was measured on a60-pt. scale (the lower the score, the poorer the attitude) . The data was subjected to a one-way analysis of variance.

ONE-WAY ANOVA FOR ATTITUDE BY COLOR
$\begin{array} { l | c | r | r | r | c } \text { SOURCE } & \text { DF } & { \text { SS } } & { \text { MS } } & \mathrm { F } & \mathrm { P } \\\hline \text { BETWEEN } & 3 & 1678.15 & 559.3833 & 59.03782 & 0.0000 \\\text { WITHIN } & 16 & 151.6 & 9.475 & & \\\text { TOTAL } & 19 & 1829.75 & & &\end{array}$

$\begin{array}{l}\text { \quad\quad\quad\quad\quad SAMPLE GROUP }\\\begin{array} { l | c | c | c } \text { COLOR } & \text { MEAN } & \text { SIZE } & \text { STD DEV } \\\hline \text { Blue } & 58.100 & 5 & 4.3589 \\\text { Green } & 57.900 & 5 & 3.9623 \\\text { Gray } & 39.100 & 5 & 1.5811 \\\text { Red } & 40.300 & 5 & 0.8367\end{array}\end{array}$

Give the null hypothesis for the ANOVA F-test shown on the printout.

A) $H _ { 0 } : p _ { \text {green } } = p _ { \text {blue } } = p _ { \text {gray } } = p _ { \text {red } }$ , where the $p ^ { \prime }$ s represent the proportion with the corresponding attitude

B) $H _ { 0 } : x _ { 1 } = x _ { 2 } = x _ { 3 } = x _ { 4 }$ , where the $x ^ { \prime }$ s represent the room colors

C) $H _ { 0 } : \mu _ { \text {green } } = \mu _ { \text {blue } } = \mu _ { \text {gray } } = \mu _ { \text {red, } }$ , where the $\mu ^ { \text {'s represent mean attitudes for the four rooms } }$

D) $H _ { 0 } : \mu _ { 1 } = \mu _ { 2 } = \mu _ { 3 } = \mu _ { 4 } = \mu _ { 5 }$ , where the $\mu _ { i }$ represent attitude means for the $i$ th person in each room