In: Statistics and Probability
Predictor |
Coefficient |
Standard Error |
Constant |
4.00 |
0.800 |
X |
-0.12 |
0.045 |
Analysis of Variance
SOURCE |
DF |
SS |
Regression |
1 |
1,400 |
Error |
18 |
3,600 |
Please answer the following questions with showing all the steps needed.
a. (8’) What has been the sample size for the above? Please explain how you obtain the answer using the numbers from the question?
b. (32’) Perform a t test and determine whether or not advertising and sales are related. Let a = 0.05.
c. (28’) Compute and interpret the coefficient of determination and correlation coefficient
d. (8’) Use the estimated regression equation and predict sales for an advertising expenditure of $4,000. Give your answer in dollars.
f. (24’) At the significant level of 0.1, please derive both P-value and critical value in an F test to determine whether or not advertising and sales are related. Explain your conclusion.