The National Highway Association is studying the relationship between the number of bidders on a highway project and the winning (lowest) bid for the project. Of particular interest is whether the number of bidders increases or decreases the amount of the winning bid.

a. Create a scatter plot of the data. What do you observe?

b. Calculate the correlation coefficient. What does it indicate about the relationship between number of bidders and the winning bid?

c. Complete a regression analysis of the relationship. Report and interpret the coefficient of determination.

d. Write the regression equation that predicts the winning bid.

e. Is the slope of the regression line significantly different from zero? Why?

f. Estimate the winning bid if there were seven bidders.

g. Compute the 95% prediction interval for a winning bid if there are seven bidders.

Transcribed Image Text:

Winning Bid (S millions), Winning Bid ($ millions), Number of Number of Project Bidders, x Project Bidders, x y 9. 5.1 10.3 9. 8.0 10 8.0 9.7 11 8.8 7.8 7.7 4 10 12 9.4 13 8.6 6 10 5.5 14 8.1 7 8.3 15 7.8 8. 11 5.5 664 7776 5.85.