Part a
Table 1: ANOVA table
Source of Variation
|
Sum of squares
|
Degrees of Freedom
|
Mean Square
|
F
|
Between treatments
|
90
|
3
|
|
|
Within treatments (Error)
|
120
|
20
|
|
|
Total
|
= 90 + 120
= 210
|
= 3+20
=23
|
|
|
The p-value for the F-value at 3,20 degrees of freedom is 0.0095. At 0.01 level of significance since p-value is less hence we reject the NULL hypothesis.
Part b
There are 4 groups in the above problem.
Number of Groups = degrees of freedom (between treatment) + 1 = 3+1 = 4
Part c
There are 21 observations in the above problem.
Number of observations = degrees of freedom (within treatment) + 1=20+1 = 21
Answer 2
Table 2: Coefficients of Regression Equation
|
Coefficients
|
Standard Error
|
t Stat
|
P-value
|
Intercept
|
136
|
13.76
|
9.881
|
0.000
|
Year (t)
|
39.18
|
2.22
|
17.664
|
0.000
|
From table 2 the trend of the number of units sold by the auto manufacturer can be written as:
- Number of Units sold (000s) = 136 + 39.18*Year
Thus, in the 11th year the number of units sold = 136+39.18*11 = 566.98 ≈ 567 (000s)
Trend of the number of units sold by major auto manufacturer
The trend shows that the number of units that can be sold by the auto manufacturer = 567000
Answer 3
Part a
ANOVA
|
|
|
|
|
|
|
df
|
SS
|
MS
|
F
|
Significance F
|
Regression
|
1
|
59.89145
|
59.89145
|
29.62415
|
0.002842
|
Residual
|
5
|
10.10855
|
2.021711
|
|
|
Total
|
6
|
70
|
|
|
|
At 0.01 level of significance there is statistically significant relationship between price and the number of flash drives sold, p-value =0.0028.
Part b
|
Coefficients
|
Standard Error
|
t Stat
|
P-value
|
Intercept
|
40.033
|
1.070
|
37.4309
|
0.0000
|
Units sold (y)
|
-1.174
|
0.216
|
-5.4428
|
0.0028
|
At 0.01 level of significance there is statistically significant relationship between price and the number of flash drives sold, p-value =0.0028.
Answer 4
Source of Variation
|
Sum of Squares
|
Degrees of Freedom
|
Mean Square
|
F
|
Between treatments
|
= 4*800 = 3200
|
= 5 – 1 = 4
|
800.00
|
|
Within treatments (Error)
|
= 10600 – 3200 = 7400
|
= 14 – 1 = 13
|
|
|
Total
|
10600
|
17
|
|
|
Answer 5
ANOVA
|
|
|
|
|
|
|
Source of Variation
|
SS
|
df
|
MS
|
F
|
P-value
|
F crit
|
Between Groups
|
324
|
2
|
162
|
40.500
|
0.000
|
4.256
|
Within Groups
|
36
|
9
|
4
|
|
|
|
Total
|
360
|
11
|
|
|
|
|
Null Hypothesis: The average sales of the three stores are equal
Alternate Hypothesis: The average sales of at least one of the stores is different
At 0.05 level of significance we reject the Null Hypothesis, p-value (0.000). Thus, the sales of the three stores are not similar, there are significant differences in the average sales of the three stores.
Answer 6
Part a
Null Hypothesis: The average sales of the three boxes are equal
Alternate Hypothesis: The average sales of at least one of the boxes is different
Part b
ANOVA
|
|
|
|
|
|
|
Source of Variation
|
SS
|
df
|
MS
|
F
|
P-value
|
F crit
|
Between Groups
|
24467.2
|
2
|
12233.6000
|
53.7111
|
0.000
|
3.8853
|
Within Groups
|
2733.2
|
12
|
227.7667
|
|
|
|
Total
|
27200.4
|
14
|
|
|
|
|
Part c
At 0.05 level of significance we reject the Null Hypothesis, p-value (0.000). Thus, the sales of the three boxes are not similar.
Answer 7
|
Brand A
|
Brand B
|
Brand C
|
Average Mileage
|
37
|
38
|
33
|
Sample Variance
|
3
|
4
|
2
|
Count
|
10
|
10
|
10
|
The total average = 37*10+38*10+33*10 = 370+380+330 = 1080
The total average mileage =
Thus SSBetween Groups = 10*(37 – 36)2+10*(38 – 36)2+10*(33 – 36)2 = 140
SSError = 10*3+10*4+10*2 = 90
ANOVA
|
|
|
|
|
Source of Variation
|
SS
|
df
|
MS
|
F
|
Between Groups
|
140
|
2
|
|
|
Within Groups
|
90
|
=29 – 2 = 27
|
|
|
Total
|
210
|
29
|
|
|
F-crit from f-table with 2, 29 at 0.05 level of significance = 3.33
Since, F-value > F-crit, hence at 0.05 level of significance there is sufficient evidence to reject Null Hypothesis. Thus, there is statistically significant differences in the mean mileage of the tyres.
Answer 8
Part a
Day
|
Tips
|
Simple Moving average
|
1
|
18
|
|
2
|
22
|
19
|
3
|
17
|
19
|
4
|
18
|
21
|
5
|
28
|
22
|
6
|
20
|
20
|
7
|
12
|
|
Part b
Days (x)
|
Forecast (Y)
|
Y’
|
Y-Y’
|
(Y-Y’)2
|
1
|
19
|
19.2
|
-0.2
|
0.04
|
2
|
19
|
19.7
|
-0.7
|
0.49
|
3
|
21
|
20.2
|
0.8
|
0.64
|
4
|
22
|
20.7
|
1.3
|
1.69
|
5
|
20
|
21.2
|
-1.2
|
1.44
|
|
|
|
0.00
|
0.86
|
The mean square error of the forecast is 0.86
Part c
The mean absolute deviation of the forecast is 0.00
Answer 9
Part a
Source of Variation
|
Degrees of Freedom
|
Sum of Squares
|
Mean Square
|
F
|
Regression
|
4
|
283940.60
|
70985.15 (MSS)
|
2.055
|
Error
|
18
|
621735.14
|
34540.84
|
|
Total
|
22
|
905675.74 (TSS)
|
|
|
The coefficient of determination =
From the regression model it can be said that 7.84% of the variability in sales of “Very Fresh Juice Company” can be predicted from the independent variables – “price per unit”, “competitor’s price”, “advertising” and “type of container.”
Part b
The corresponding p-value for F is 0.129. At 0.05 level of significance we do not have sufficient evidence to reject Null Hypothesis. Hence, the model is statistically not significant.
Significance value can be found in MS-EXCEL by =F.DIST.RT(2.055,4,18)
Part c
The total sample size = 23 (Total +1)
Answer 10
ANOVA
|
|
|
|
|
|
|
df
|
SS
|
MS
|
F
|
Significance F
|
Regression
|
2
|
118.8474369
|
59.4237
|
40.9216
|
0.000
|
Residual
|
9
|
13.0692
|
1.4521
|
|
|
Total
|
11
|
131.9166667
|
|
|
|
|
|
|
|
|
|
|
Coefficients
|
Standard Error
|
t Stat
|
P-value
|
|
Intercept
|
118.5059
|
33.5753
|
3.5296
|
0.0064
|
|
x1
|
-0.0163
|
0.0315
|
-0.5171
|
0.6176
|
|
x2
|
-1.5726
|
0.3590
|
-4.3807
|
0.0018
|
|
Part a
The price of the stock can be predicted from the equation
- y = 118.5059 – 0.0163*x1– 1.5726*x2
Part b
From the regression equation it can be said that:
- For every 100 stocks of company sold the price of Rawlon Inc. stock would decrease by 0.0163
- For every million increase in exchange of the New York Stock Exchange the price of Rawlon Inc. Stock would decrease by 1.5726.
Part c
At 95% confidence level the volume of exchange of New York stock exchange is statistically significant (p-value = 0.0018).
At 95% confidence level the number of shares sold by Rawlon Inc. is statistically not significant (p-value = 0.6176).
Part d
For 94500 stocks sold and 16million the volume of exchange on the New York Stock Exchange the price of the stock would be:
- y = 118.5059 – 0.0163*x1– 1.5726*x2
- y =118.5059 – 0.0163*945 – 1.5726*16
- y = 77.95