Question

QUESTION 1:

The Masters is one of the four major golf tournaments. Only the 60 golfers with the lowest two-round total advance to the final two rounds (unless several people are tied for 60th place, in which case all those tied for 60th place advance). Suppose that for a certain year the least-squares line for predicting second-round scores from first-round scores has equation

yˆ=51.43+0.315xy^=51.43+0.315x

(a) Find the predicted (±±0.001) second-round scores for a player who shot 80 in the first round

(b) Find the predicted (±±0.001) second-round scores for a player who shot 70 in the first round

QUESTION 2:

An online article suggested that for each additional person who took up regular running for exercise, the number of cigarettes smoked daily would decrease by 0.178.
If we assume that 43 million cigarettes would be smoked per day if nobody ran, what is the equation of the regression line for predicting number of cigarettes smoked per day from the
number of people who regularly run for exercise?

Denote (new runners) as xx. Do not include commas in your answer

Answer 1

QUESTION 1:

=51.43+0.315x

(a)

The predicted second-round score for a player who shot 80 in the first round (x =80) is: =51.43+0.315(80) =76.63

Predicted interval =76.63 0.001 =(76.629, 76.631)

(b)

The predicted second-round score for a player who shot 70 in the first round (x =70) is: =51.43+0.315(70) =73.48

Predicted interval =73.48 0.001 =(73.479, 73.481)

QUESTION 2:

Independent variable, X =The number of persons who took up regular running for exercise.

Dependent variable, Y =The number of cigarettes smoked daily.

Given:

Slope of the regression line is: b = -0.178

Y-intercept (i.e., the value of Y when X =0) is: a =43 million

So, the equation of the regression line for predicting number of cigarettes smoked per day(Y) from the number of people who regularly run for exercise(X) is: =a+bX which is as follows:

Number of cigarettes smoked per day =43 million - 0.178(number of people who regularly run for exercise)