1. You are given the following data on sales (in tens of thousands of dollars) and advertising expenditure (in thousands of dollars):
a. Calculate the regression equation of sales on advertising expenditures.
b. Construct a 95% confidence interval for the mean value of Y if X =9.
c. Use a 5% level of significance and test
d. Predict sales if $6,000 is spent on advertising.
e. Calculate a 95% confidence interval for the individual value of Y if X = 6.
2. Suppose a statistician obtained the following estimated regression model
where is a dummy variable indicating the gender of the ith individual and =1 if the individual is a male. Suppose another statistician estimated the model using the same data but defined if the individual is female.
a. What would happen to the constant term?
b. What would happen to the coefficient of ?
c. What would happen to the coefficient of ?
3. A regression model relating xs, number of sales persons at branch offices, to y, annual sales at the office ($1000s), has been developed. The computer output from a regression analysis of the data follows.
The regression equation is
a. Write the estimated regression equation.
b. How many branch offices were involved in the study?
c. Compute the F statistic and test the significance of the relationship at a .05 level of significance.
Attachment:- BA.rar