A Random Sample of 19 Companies from the Forbes 500

Multiple Choice

A random sample of 19 companies from the Forbes 500 list was selected, and the relationship between sales (in hundreds of thousands of dollars) and profits (in hundreds of thousands of dollars) was investigated by regression. The following simple linear regression model was used: profits =  +  (sales) , where the deviations were assumed to be independent and Normally distributed, with mean 0 and standard deviation . This model was fit to the data using the method of least squares. The following results were obtained from statistical software. r² = 0.662
S = 466.2 An approximate 90% confidence interval for the slope  in the simple linear regression model is:

A) -176.66 to -176.63.
B) 0.079 to 0.106.
C) 0.071 to 0.114.
D) None of the answer options is correct.