Chapter 3.2, Problem 41E

(a)

To determine

To interpret the slope of the regression line.

Explanation of Solution

It is given in the question the regression line that,

  $\widehat{y}=60.7+0.139x$

Thus as we know that the slope is coefficient of x in the least square regression equation and represents the average increase or decrease of y per unit of x . Thus, the slope is,

  $b_1=0.139$

This then implies that on average, the number of wins increase by $0.139$ wins per millions of dollars.

(b)

To determine

To explain does the value of the y -intercept have meaning in this context and if so then interpret the y -intercept.

Answer to Problem 41E

It does not have meaning.

Explanation of Solution

It is given in the question the regression line that,

  $\widehat{y}=60.7+0.139x$

As we know that, the y -intercept is the constant in the least square regression equation and represents the average y -value when x is zero. Thus, the y -intercept is as:

  $b_0=60.7$

This then implies that there are $60.7$ wins when the payroll is zero millions of dollars. However, it is not reasonable to have a payroll of zero millions of dollars and the value of the y intercept does not have meaning in this context.