Examine the following data set:
y x
25…………………..10
35…………………..10
14…………………..10
45…………………..20
52…………………..20
41…………………..20
65…………………..30
63…………………..30
68…………………..30
a. Determine the estimated regression equation for this data set.
b. Calculate the residuals for this regression equation.
c. Produce the appropriate residual plot to determine if the linear function is the appropriate regression function for this data set.
d. Use a residual plot to determine if the residuals have a constant variance.
e. Produce a residual plot to determine if the residuals are independent. Assume the order of appearance is the time order of the data.
f. Use a probability plot to determine if the error terms are normally distributed.