Additive regression model for the Apple prices is: Dependent variable is: Apples R squared = 51.9% R squared (adjusted) = 34.9% s = 0.1108 with 47 - 13 = 34 degrees of freedom
|
Variable Intercept
|
Coefficient - 114.825
|
SE(Coeff) 29.46
|
t-ratio - 3.90
|
P-value 0.0004
|
|
Time
|
0.057746
|
0.0147
|
3.94
|
0.0004
|
|
Jan
|
- 0.001438
|
0.0783
|
- 0.018
|
0.9855
|
|
Feb
|
- 0.007062
|
0.0783
|
- 0.090
|
0.9287
|
|
Mar
|
0.003626
|
0.0784
|
0.046
|
0.9634
|
|
Apr
|
0.015064
|
0.0784
|
0.192
|
0.8488
|
|
may
|
0.058751
|
0.0785
|
0.749
|
0.4592
|
|
Jun
|
0.115689
|
0.0786
|
1.47
|
0.1501
|
|
Jul
|
0.173627
|
0.0787
|
2.21
|
0.0342
|
|
Aug
|
0.169815
|
0.0788
|
2.16
|
0.0383
|
|
Sep
|
0.049253
|
0.0789
|
0.624
|
0.5368
|
|
Oct
|
0.006191
|
0.0791
|
0.078
|
0.9381
|
|
Nov
|
- 0.014249
|
0.0847
|
- 0.168
|
0.8675
|
a) What is the name for the kind of variable called Jan in this model?
b) Why is there no predictor variable for December?
c) Is there evidence of a cyclic component in these data?