Consider the accompanying data on x 5 advertising share and y 5 market share for a particular brand of soft drink during 10 randomly selected years.

x .103 .072 .071 .077 .086 .047 .060 .050 .070 .052 y .135 .125 .120 .086 .079 .076 .065 .059 .051 .039

a. Construct a scatterplot for these data. Do you think the simple linear regression model would be appropriate for describing the relationship between x and y?

b. Calculate the equation of the estimated regression line and use it to obtain the predicted market share when the advertising share is .09.

c. Compute r 2 . How would you interpret this value?

d. Calculate a point estimate of s. On how many degrees of freedom is your estimate based?