Ex 27 (bikes):

Bike Prices. Consumer Reports tested 19 different brands and models of road, fitness, and

comfort bikes. Road bikes are designed for long road trips; fitness bikes are designed for regular

workouts or daily commutes; and comfort bikes are designed for leisure rides on typically flat

roads. The following data show the type, weight (lb.), and price ($) for the 19 bicycles tested.

1.

2.

3.

Use the following dummy variables to develop an estimated regression equation that

can be used to predict the price given the type of bike: Type_Fitness = 1 if the bike is a

fitness bike, 0 otherwise; and Type_Confort = 1 if the bike is a comfort bike; 0 otherwise.

Compare the results obtained to the results obtained in part (b).

4. To account for possible interaction between the type of bike and the weight of the bike,

develop a new estimated regression equation that can be used to predict the price of

the bike given the type, the weight of the bike, and any interaction between weight and

Develop a scatter diagram with weight as the independent variable and price as the

dependent variable. Does a simple linear regression model appear to be appropriate?

Develop an estimated multiple regression equation with x = weight and x^2 as the two

independent variables.

each of the dummy variables defined in part (c). What estimated regression equation

appears to be the best predictor of price? Explain.

Bikes.xlsx

Additional Exercise (required):

1. For a recent season, several variables were recorded for 125 professional golfers. We are interested

in using multiple regression to predict Earnings ($) from the predictors indicated in the backward

elimination output (with some deletions) below. Briefly explain your answers.