In: Statistics and Probability
The Consumer Reports customer satisfaction survey is based upon 148,599 visits to full service restaurant chains. Assume this data set is representative of the results reported. The variable restaurant “type” indicates whether the restaurant is an Italian restaurant or a seafood/steakhouse. Price indicates the average amount a person paid for dinner and drinks minus the tip. Score reflects overall customer satisfaction and a score of 80 can be interpreted as very satisfied. Assume alpha = 0.05 for all parts of this question.
First, develop a dummy variable to indicate the restaurant’s “type”. Use a dummy variable code of ‘0’ to indicate an Italian restaurant and a ‘1’ to indicate a seafood/steakhouse. Develop a regression equation predicting the customer satisfaction score based upon both price and restaurant type.
What is the RSQ (R-squared) value? (Note: This is regular R^2, NOT Adjusted R^2).
Restaurant | Type | Price ($) | Score |
Bertucci's | Italian | 16 | 77 |
Black Angus Steakhouse | Seafood/Steakhouse | 24 | 79 |
Bonefish Grill | Seafood/Steakhouse | 26 | 85 |
Bravo! Cucina Italiana | Italian | 18 | 84 |
Buca di Beppo | Italian | 17 | 81 |
Bugaboo Creek Steak House | Seafood/Steakhouse | 18 | 77 |
Carrabba's Italian Grill | Italian | 23 | 86 |
Charlie Brown's Steakhouse | Seafood/Steakhouse | 17 | 75 |
Il Fornaio | Italian | 28 | 83 |
Joe's Crab Shack | Seafood/Steakhouse | 15 | 71 |
Johnny Carino's Italian | Italian | 17 | 81 |
Lone Star Steakhouse & Saloon | Seafood/Steakhouse | 17 | 76 |
LongHorn Steakhouse | Seafood/Steakhouse | 19 | 81 |
Maggiano's Little Italy | Italian | 22 | 83 |
McGrath's Fish House | Seafood/Steakhouse | 16 | 81 |
Olive Garden | Italian | 19 | 81 |
Outback Steakhouse | Seafood/Steakhouse | 20 | 80 |
Red Lobster | Seafood/Steakhouse | 18 | 78 |
Romano's Macaroni Grill | Italian | 18 | 82 |
The Old Spaghetti Factory | Italian | 12 | 79 |
Uno Chicago Grill | Italian | 16 | 76 |
Answer:
a) regression equation : Score = 70.4431 +0.5734*Price - 3.0382*type_dummy
b) RSQ (R-squared) value=0.5262
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Solution:
Part a.
Regression analysis using MS-EXCEL gives following results.
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.725419 | |||||||
R Square | 0.526233 | |||||||
Adjusted R Square | 0.473593 | |||||||
Standard Error | 2.64219 | |||||||
Observations | 21 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 2 | 139.5771 | 69.78856 | 9.996691 | 0.001202 | |||
Residual | 18 | 125.661 | 6.981166 | |||||
Total | 20 | 265.2381 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
Intercept | 70.44306 | 3.002376 | 23.46244 | 6.02E-15 | 64.1353 | 76.75082 | 64.1353 | 76.75082 |
type_dummy | -3.03821 | 1.155225 | -2.62997 | 0.016992 | -5.46525 | -0.61117 | -5.46525 | -0.61117 |
Price ($) | 0.573429 | 0.154574 | 3.709728 | 0.001604 | 0.24868 | 0.898177 | 0.24868 | 0.898177 |
Using This we get the regression equation as,
Score = 70.4431 +0.5734*Price - 3.0382*type_dummy
b) RSQ (R-squared) value=0.5262
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you!
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Input Data
Restaurant | Type | type_dummy | Price ($) | Score |
Bertucci's | Italian | 0 | 16 | 77 |
Black Angus Steakhouse | Seafood/Steakhouse | 1 | 24 | 79 |
Bonefish Grill | Seafood/Steakhouse | 1 | 26 | 85 |
Bravo! Cucina Italiana | Italian | 0 | 18 | 84 |
Buca di Beppo | Italian | 0 | 17 | 81 |
Bugaboo Creek Steak House | Seafood/Steakhouse | 1 | 18 | 77 |
Carrabba's Italian Grill | Italian | 0 | 23 | 86 |
Charlie Brown's Steakhouse | Seafood/Steakhouse | 1 | 17 | 75 |
Il Fornaio | Italian | 0 | 28 | 83 |
Joe's Crab Shack | Seafood/Steakhouse | 1 | 15 | 71 |
Johnny Carino's | Italian | 0 | 17 | 81 |
Lone Star Steakhouse & Saloon | Seafood/Steakhouse | 1 | 17 | 76 |
Longhorn Steakhouse | Seafood/Steakhouse | 1 | 19 | 81 |
Maggiano's Little Italy | Italian | 0 | 22 | 83 |
McGrath's Fish House | Seafood/Steakhouse | 1 | 16 | 81 |
Olive Garden | Italian | 0 | 19 | 81 |
Outback Steakhouse | Seafood/Steakhouse | 1 | 20 | 80 |
Red Lobster | Seafood/Steakhouse | 1 | 18 | 78 |
Romano's Macaroni Grill | Italian | 0 | 18 | 82 |
The Old Spaghetti Factory | Italian | 0 | 12 | 79 |
Uno Chicago Grill | Italian | 0 | 16 | 76 |