In: Statistics and Probability
1. The owner of the Original Italian Pizzeria restaurant chain would like to predict the sales of her specialty deep-dish pizza. She has gathered data on the monthly sales of deep-dish pizzas at her restaurants and observations on other potentially relevant variables for each of her 15 restaurants in Northern California. The data is found in the file “DeepDishPizza.”
a. Create two (2) scatter charts. The first one will be a scatter chart of Quantity Sold (on the y-axis) and the variable Disposable Income per Household (on the x-axis). The second one will be a scatter chart of Quantity Sold (on the y-axis) and the variable Monthly Advertising Expenditures. Be sure to label the axes correctly.
b. Using the Regression function in Data Analysis, estimate a regression equation between Quantity Sold and Disposable Income per Household. Type your estimated equation in a text box. How would you explain the interpretation of the coefficient on Disposable Income per Household and the R 2 to the owner?
c. At a level of significance of 5%, test the null hypothesis that the coefficient on Disposable Income per Household is 0. Clearly explain your answer.
d. The owner also wants to know whether advertising expenses by her firm have any effect on the number of deep-dish pizzas sold. Using the Regression function in Data Analysis, estimate a regression equation between Quantity Sold and Disposable Income per Household Type and Monthly Advertising Expenditure. Type your estimated equation in a text box. How would you now explain both estimated coefficients and the R 2 to the owner?
e. At a level of significance of 5%, test the null hypothesis that the coefficient on each independent variable is 0. Clearly explain your answer.
f. For the equation you estimated in (d), what is the interpretation of the F-test? Is it significant at a level of significance of 5%?
g. Suppose the Disposable Income per Household is equal to $43,000. Using your estimated regression equation in (d), what should the owner plan on Monthly Advertising Expenditures per restaurant if she wants to sell 58,000 deep-dish pizza per restaurant? Show your work.
Restaurant Number | Quantity Sold | Disposable Income per Household | Monthly Advertising Expenditures |
1 | 85,300 | $42,100 | $64,800 |
2 | 40,500 | $38,300 | $42,800 |
3 | 61,800 | $41,000 | $58,600 |
4 | 50,800 | $43,300 | $46,500 |
5 | 60,600 | $44,000 | $50,700 |
6 | 79,400 | $41,200 | $60,100 |
7 | 71,400 | $41,700 | $55,600 |
8 | 70,700 | $43,600 | $57,900 |
9 | 55,600 | $39,900 | $52,100 |
10 | 70,900 | $44,800 | $60,700 |
11 | 77,200 | $41,800 | $64,400 |
12 | 63,200 | $44,200 | $55,600 |
13 | 71,100 | $40,100 | $60,900 |
14 | 55,500 | $39,100 | $47,200 |
15 | 42,100 | $38,000 | $46,100 |
a)
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b)
SUMMARY OUTPUT | ||||||
Regression Statistics | ||||||
Multiple R | 0.483483 | |||||
R Square | 0.233756 | |||||
Adjusted R Square | 0.174814 | |||||
Standard Error | 11962.14 | |||||
Observations | 15 | |||||
ANOVA | ||||||
df | SS | MS | F | Significance F | ||
Regression | 1 | 5.67E+08 | 5.67E+08 | 3.965877 | 0.067871 | |
Residual | 13 | 1.86E+09 | 1.43E+08 | |||
Total | 14 | 2.43E+09 | ||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | |
Intercept | -58385.9 | 61402.83 | -0.95087 | 0.359016 | -191039 | 74266.82 |
Disposable Income per Household | 2.93996 | 1.47629 | 1.991451 | 0.067871 | -0.24937 | 6.129291 |
Y = -58385.9 + 2.93996 *x
R Square = 0.233756
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c)
p value for slope = 0.067871
p value > 0.045 , not significnt
.............
d)
SUMMARY OUTPUT | |||||
Regression Statistics | |||||
Multiple R | 0.93842406 | ||||
R Square | 0.880639716 | ||||
Adjusted R Square | 0.860746335 | ||||
Standard Error | 4914.014692 | ||||
Observations | 15 | ||||
ANOVA | |||||
df | SS | MS | F | Significance F | |
Regression | 2 | 2.14E+09 | 1.07E+09 | 44.26798 | 2.89E-06 |
Residual | 12 | 2.9E+08 | 24147540 | ||
Total | 14 | 2.43E+09 | |||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | |
Intercept | -53658.53808 | 25230.92 | -2.1267 | 0.054877 | -108632 |
Disposable Income per Household | 0.613266618 | 0.671587 | 0.913161 | 0.379139 | -0.84999 |
Monthly Advertising Expenditures | 1.673363643 | 0.207499 | 8.064432 | 3.46E-06 | 1.221262 |
y = -53658.538 +0.6132666*X1 +1.67336*x2
R Square = 0.8806
.................
e)
p value for monthly expd = 3.46313E-06
p value < 0.05, significant
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f)
p value = 2.89E-06
p value < 0.05
test is signifcant
modal is good
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Please revert back in case of any doubt.
Please upvote. Thanks in advance.