Use the Following for Questions
a Sales Manager Was $= - 0.48 + 7.42$

Essay

Use the following for questions
A sales manager was interested in determining if there is a relationship between college GPA and sales performance among salespeople hired within the last year. A sample of recently hired salespeople was selected and college GPA and the number of units sold last month recorded. Below are the scatterplot, regression results, and residual plots for these data. The regression equation is
Units Sold $= - 0.48 + 7.42$ GPA
$\begin{array} { l r r r r } \text { Predictor } & \text { Coef } & \text { SE Coef } & \text { T } & \text { P } \\ \text { Constant } & - 0.484 & 3.256 & - 0.15 & 0.884 \\ \text { GPA } & 7.423 & 1.044 & 7.11 & 0.000 \end{array}$
$\mathrm { S } = 1.57429 \quad \mathrm { R } - \mathrm { Sq } = 78.3 \% \mathrm { \circ } \quad \mathrm { R } - \mathrm { Sq } ( \mathrm { adj } ) = 76.8 \%$
Analysis of Variance
$\begin{array} { l r r r r r } \text { Source } & \text { DF } & \text { SS } & \text { MS } & \text { F } & \text { P } \\ \text { Regression } & 1 & 125.30 & 125.30 & 50.56 & 0.000 \\ \text { Residual Error } & 14 & 34.70 & 2.48 & & \\ \text { Total } & 15 & 160.00 & & & \end{array}$ Answer:
-What is the independent variable in this regression? Write the null and alternative
hypothesis to test the slope of this variable.