In: Statistics and Probability
Thailand, Vietnam, and China have had a fast population increase over the last 10 years. It is expected that the growth will continue over the next 10 years. Therefore, many food companies that want to build new restaurants in these countries. McDonald's is no exception. The director of planning for McDonald's wants to study adding more restaurants in these countries. He believes there are two main factors that indicate the amount families spend on Food. The first is their income and the other is the number of people in the family. The director gathered the following sample information.
Family | Food | Income | Family Size | |||||
1 | $ | 3.90 | $ | 73.98 | 2 | |||
2 | 4.08 | 54.90 | 2 | |||||
3 | 5.76 | 142.16 | 4 | |||||
4 | 3.48 | 52.02 | 1 | |||||
5 | 4.20 | 65.70 | 2 | |||||
6 | 4.80 | 53.64 | 4 | |||||
7 | 4.32 | 79.74 | 3 | |||||
8 | 5.04 | 68.58 | 4 | |||||
9 | 6.12 | 165.60 | 5 | |||||
10 | 3.24 | 64.80 | 1 | |||||
11 | 4.80 | 138.42 | 3 | |||||
12 | 3.24 | 125.82 | 1 | |||||
13 | 5.76 | 77.58 | 7 | |||||
14 | 4.48 | 159.28 | 2 | |||||
15 | 6.60 | 30.80 | 2 | |||||
16 | 5.40 | 141.30 | 3 | |||||
17 | 6.00 | 36.90 | 5 | |||||
18 | 5.40 | 56.88 | 4 | |||||
19 | 3.36 | 71.82 | 1 | |||||
20 | 4.68 | 69.48 | 3 | |||||
21 | 4.32 | 54.36 | 2 | |||||
22 | 5.52 | 87.66 | 5 | |||||
23 | 4.56 | 38.16 | 3 | |||||
24 | 5.40 | 43.74 | 7 | |||||
25 | 7.33 | 45.73 | 5 | |||||
Food and income are reported in thousands of dollars per year, and the variable size refers to the number of people in the household.
Click here for the Excel Data File
a-1. Develop a correlation matrix. (Round your answers to 3 decimal places. Negative amounts should be indicated by a minus sign.)
a-2. Do you see any problem with multicollinearity?
b-1. Determine the regression equation. (Round your answer to 3 decimal places.)
b-2. How much does an additional family member add to the amount spent on food? (Round your answer to the nearest dollar amount.)
c-1. What is the value of R2? (Round your answer to 3 decimal places.)
c-2. Complete the ANOVA (Leave no cells blank - be certain to enter "0" wherever required. Round SS, MS to 4 decimal places and F to 2 decimal places.)
c-3. State the decision rule for 0.05 significance level. H0: = β1 = β2 = 0; H1: Not all βi's = 0. (Round your answer to 2 decimal places.)
c-4. Can we reject H0: = β1 = β2 = 0?
d-1. Complete the table given below. (Leave no cells blank - be certain to enter "0" wherever required. Round Coefficient, SE Coefficient, P to 4 decimal places and T to 2 decimal places.)
d-2. Would you consider deleting either of the independent variables?
From the graph the residuals appear normally distributed.
True
False
There is a homoscedasticity problem.
There is no homoscedasticity problem
Thailand, Vietnam, and China have had a fast population increase over the last 10 years. It is expected that the growth will continue over the next 10 years. Therefore, many food companies that want to build new restaurants in these countries. McDonald's is no exception. The director of planning for McDonald's wants to study adding more restaurants in these countries. He believes there are two main factors that indicate the amount families spend on Food. The first is their income and the other is the number of people in the family. The director gathered the following sample information.
Family | Food | Income | Family Size | |||||
1 | $ | 3.90 | $ | 73.98 | 2 | |||
2 | 4.08 | 54.90 | 2 | |||||
3 | 5.76 | 142.16 | 4 | |||||
4 | 3.48 | 52.02 | 1 | |||||
5 | 4.20 | 65.70 | 2 | |||||
6 | 4.80 | 53.64 | 4 | |||||
7 | 4.32 | 79.74 | 3 | |||||
8 | 5.04 | 68.58 | 4 | |||||
9 | 6.12 | 165.60 | 5 | |||||
10 | 3.24 | 64.80 | 1 | |||||
11 | 4.80 | 138.42 | 3 | |||||
12 | 3.24 | 125.82 | 1 | |||||
13 | 5.76 | 77.58 | 7 | |||||
14 | 4.48 | 159.28 | 2 | |||||
15 | 6.60 | 30.80 | 2 | |||||
16 | 5.40 | 141.30 | 3 | |||||
17 | 6.00 | 36.90 | 5 | |||||
18 | 5.40 | 56.88 | 4 | |||||
19 | 3.36 | 71.82 | 1 | |||||
20 | 4.68 | 69.48 | 3 | |||||
21 | 4.32 | 54.36 | 2 | |||||
22 | 5.52 | 87.66 | 5 | |||||
23 | 4.56 | 38.16 | 3 | |||||
24 | 5.40 | 43.74 | 7 | |||||
25 | 7.33 | 45.73 | 5 | |||||
Food and income are reported in thousands of dollars per year, and the variable size refers to the number of people in the household.
Click here for the Excel Data File
a-1. Develop a correlation matrix.
the correlation matrix is
Food | Income | Family Size | |
Food | 1 | ||
Income | -0.021 | 1 | |
Family Size | 0.723 | -0.041 | 1 |
a-2. Do you see any problem with multicollinearity?
NO
using excel>data>data analysis >regression
we have
SUMMARY OUTPUT | ||||||
Regression Statistics | ||||||
Multiple R | 0.723284 | |||||
R Square | 0.523139 | |||||
Adjusted R Square | 0.479788 | |||||
Standard Error | 0.767853 | |||||
Observations | 25 | |||||
ANOVA | ||||||
df | SS | MS | F | Significance F | ||
Regression | 2 | 14.22999 | 7.114993 | 12.06754 | 0.00029 | |
Residual | 22 | 12.97115 | 0.589598 | |||
Total | 24 | 27.20114 | ||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | |
Intercept | 3.416912 | 0.460734 | 7.416242 | 2.03E-07 | 2.461409 | 4.372415 |
Income | 0.000241 | 0.003871 | 0.062135 | 0.951017 | -0.00779 | 0.008269 |
Family Size | 0.443042 | 0.090218 | 4.910765 | 6.54E-05 | 0.25594 | 0.630143 |
b-1. Determine the regression equation.
the regression equation is
Food = 3.417 +0.000 *Income +0.443*Family size
b-2. $0.443$ an additional family member add to the amount spent on food
c-1. the value of R2 is 0.523
c-2. Complete the ANOVA (Leave no cells blank - be certain to enter "0" wherever required. Round SS, MS to 4 decimal places and F to 2 decimal places.)
df | SS | MS | F | |
Regression | 2 | 14.2300 | 7.1150 | 12.07 |
Residual | 22 | 12.9712 | 0.5896 | |
Total | 24 | 27.2011 |
c-3. State the decision rule for 0.05 significance level. H0: = β1 = β2 = 0; H1: Not all βi's = 0.
Reject Ho if F > 3.44
c-4. Can we reject H0: = β1 = β2 = 0
yes
d-1. Complete the table given below. (Leave no cells blank - be certain to enter "0" wherever required. Round Coefficient, SE Coefficient, P to 4 decimal places and T to 2 decimal places.)
Coefficients | Standard Error | t Stat | P-value | |
Intercept | 3.4169 | 0.4607 | 7.41 | 0.0000 |
Income | 0.0002 | 0.0039 | 0.0621 | 0.9510 |
Family Size | 0.4430 | 0.0902 | 4.9108 | 0.0000 |
d-2. Would you consider deleting either of the independent variables?
yes , the income variable should be deleted
* graph not given