Suppose That You Are to Choose the Best Machine from Among

Essay

Suppose that you are to choose the best machine from among three different brands. You have samples of output from each of the three brands. One characteristic of a high quality machine is consistency. Of course, in any batch of output there will be some that are a little too large and some that are a little too small. For the data below, calculate the appropriate standard deviations and use them to recommend the "best quality machine."The data are deviations from specifications in thousandths of an inch. (Can you eyeball the data and come to a preliminary conclusion?) $$\begin{array} { c c c } \text { Brand A } & \text { Brand B } & \text { Brand C } \\\hline - 3 & - 2 & - 5 \\- 11 & 7 & 3 \\8 & 3 & 2 \\2 & - 6 & 1 \\4 & - 2 & - 1\end{array}$$