To Test Whether the Time Required to Fully Load a Standard

Essay

To test whether the time required to fully load a standard delivery truck is the same for three work shifts (day, evening, and night), NatEx obtained the following data on the time (in minutes) needed to pack a truck. Use these data to test whether the population mean times for loading a truck differ for the three work shifts. Use α = .05.
​ $$\begin{array} { c c c c } \text { Observation } & \text { Day Shift } & \text { Evening Shift } & \text { Night Shift } \\\hline 1 & 92 & 83 & 89 \\2 & 81 & 93 & 97 \\3 & 103 & 79 & 95 \\4 & 77 & 102 & 88 \\5 & 82 & 84 & 106 \\\hline \text { Sample mean } & 87.0 & 88.2 & 95.0 \\\text { Sample variance } & 110.5 & 85.7 & 52.5\end{array}$$ ​