The Following Results Were Obtained from a Multiple Regression Analysis $\begin{array} { l l l } & d f & S S \\ \text { Regression } & 2 & 562.363 \\ \text { Residual } & 9 & 225.326 \end{array}$

The following results were obtained from a multiple regression analysis of supermarket profitability.The dependent variable, y, is the profit (in thousands of dollars) and the independent variables, x₁ and x₂, are the food sales and nonfood sales (also in thousands of dollars). ANOVA
$\begin{array} { l l l } & d f & S S \\ \text { Regression } & 2 & 562.363 \\ \text { Residual } & 9 & 225.326 \end{array}$
Total ​ $\begin{array}{lcc}& \text { Coefficients } & \text { Standara Error } \\\text { Intercept } & -15.0621 & \\\mathrm{x}_{1} & 0.0972 & 0.054 \\\mathrm{x}_{2}& 0.2484 & 0.092\end{array}$ ​
a.
Write the estimated regression equation for the relationship between the variables.
b.
Compute the multiple coefficient of determination and fully interpret its meaning.
c.
Carry out a test to determine whether y is significantly related to the independent variables. Use a .05 level of significance.
d.
Carry out a test to determine if there is a significant relationship between x₁ and y. Use a .05 level of significance.
e.
How many supermarkets were used in the sample here?