In: Statistics and Probability
Making a forecast for the following daily closing price level which method arrses, holt and holt-winter) give reason . forecast the last closing price level?
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
8039 |
8088 |
8083 |
8169 |
8164 |
8192 |
8209 |
8209 |
8225 |
8219 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
8200 |
8255 |
8250 |
8260 |
8293 |
8299 |
8284 |
8299 |
8299 |
1. (20 points) i am going to use ________ method because _____
2.(20 points) Forecast value for the 19th price level is ____
According to the following table do you think that there exist a relationship between dependent variable (GNP) and independent variables (x1).
3.Write down the hypothesis (10 points)
(1) I am going to use quadratic polynomial method because scatter plot showed some curve on the trend
the quadratic model is given as y=8037.35+26.1642*t-0.6659*t^2
SUMMARY OUTPUT | ||||||
Regression Statistics | ||||||
Multiple R | 0.967423 | |||||
R Square | 0.935908 | |||||
Adjusted R Square | 0.927896 | |||||
Standard Error | 20.69577 | |||||
Observations | 19 | |||||
ANOVA | ||||||
df | SS | MS | F | Significance F | ||
Regression | 2 | 100071.6 | 50035.8 | 116.8201 | 2.85E-10 | |
Residual | 16 | 6853.038 | 428.3149 | |||
Total | 18 | 106924.6 | ||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | |
Intercept | 8037.35 | 15.88685 | 505.9122 | 4.58E-35 | 8003.671 | 8071.028 |
t | 26.1642 | 3.657936 | 7.152723 | 2.3E-06 | 18.40973 | 33.91868 |
t2 | -0.66593 | 0.177687 | -3.74777 | 0.001756 | -1.04261 | -0.28925 |
(2) for t=19 the y^=8037.35+26.1642*19-0.6659*19*19=8294.08
(3) the correlation =r=0.9378
null hypothesis H0:=0 and
alternate hypothesis Ha:
we use t-test for its significance test and
t =r/sqrt[(1—r2)/(n—2)]=0.9378/sqrt((1-0.9378*0.9378)/(19-2))=11.13 with n-2=19-2=17 df
and critical t(0.05/2.17)=2.11 is less than calculated t=11.13, so we reject H0 and conclude that there is significant correlation between dependent variable (GNP) and independent variables (x1).