Nancy, Inc A Compute the Overall Mean

Essay

Nancy, Inc. has three stores located in three different areas. Random samples of the sales of the three stores In
$1,000) are shown below.
$$\begin{array} { c c c } \text { Store 1 } & \text { Store 2 } &\text { Store 3 } \\46 & 34 & 33 \\47 & 36 & 31 \\45 & 35 & 35 \\42 & 39 &\\45\end{array}$$
a. Compute the overall mean .
b. At 95% confidence, test to see if there is a significant difference in the average sales of the three stores.