Chapter 8, Problem 15E

(a)

To determine

To explain what are the variables and units in this regression.

Answer to Problem 15E

Price in thousands of dollars and the Size in square feet.

Explanation of Solution

It is given in the question that, a random sample of records of sales of homes gives the price and size of homes. A regression to predict price from size has an R -squared of $\text{71}\text{.4\%}$ . The residual plot indicated that a linear model is appropriate. The variables in this regression are Price in thousands of dollars and the Size in square feet.

(b)

To determine

To explain what units does the slope have.

Answer to Problem 15E

Dollar per square foot.

Explanation of Solution

It is given in the question that, a random sample of records of sales of homes gives the price and size of homes. A regression to predict price from size has an R -squared of $\text{71}\text{.4\%}$ . The residual plot indicated that a linear model is appropriate. Thus, the slope units will be in dollar per square foot.

(c)

To determine

To explain do you think the slope would be positive or negative.

Answer to Problem 15E

The slope would be positive.

Explanation of Solution

It is given in the question that, a random sample of records of sales of homes gives the price and size of homes. A regression to predict price from size has an R -squared of $\text{71}\text{.4\%}$ . Thus, we can say that the slope of this regression will be positive because larger homes should be costing more. Therefore, it will be positive.