QuickFix. The general manager of QuickFix, a chain of quick-service, no-appointment auto repair shops, wants to develop
Question:
QuickFix. The general manager of QuickFix, a chain of quick-service, no-appointment auto repair shops, wants to develop a model to forecast monthly vehicles served at any particular shop based on four factors: garage bays, population within 5-mile radius, interstate highway access (1 = convenient access, 0 = otherwise), and time of year (1 = winter, 0 = otherwise). He believes that, all else equal, shops near an interstate will service more vehicles and that more vehicles will be serviced in the winter due to battery and tire issues. A sample of 19 locations has been obtained. A portion of the data is shown in the accompanying table.
a. Estimate the regression equation relating vehicles serviced to the four explanatory variables.
b. Interpret each of the slope coefficients.
e. Predict vehicles serviced in July for a particular location with 5 garage bays, a population of 40,000, and convenient interstate access.
Vehicles Served (Per Month) | Garage Bays | Population in 5-mile radius (000’s) | Convenient interstate access? (1=yes, 0=no) | Time of year? (1=winter, 0=other) |
200 | 3 | 15 | 0 | 0 |
351 | 3 | 22 | 0 | 1 |
382 | 3 | 35 | 1 | 1 |
214 | 4 | 30 | 0 | 0 |
250 | 4 | 37 | 0 | 0 |
288 | 4 | 42 | 0 | 1 |
352 | 4 | 45 | 1 | 0 |
345 | 4 | 48 | 1 | 0 |
410 | 4 | 62 | 1 | 1 |
325 | 5 | 25 | 0 | 0 |
317 | 5 | 29 | 0 | 1 |
344 | 5 | 36 | 1 | 0 |
376 | 5 | 39 | 1 | 0 |
369 | 5 | 44 | 1 | 0 |
494 | 5 | 72 | 1 | 1 |
318 | 6 | 49 | 0 | 0 |
354 | 6 | 54 | 1 | 0 |
512 | 6 | 77 | 1 | 1 |
464 | 6 | 74 | 1 | 1 |
Business Statistics
ISBN: 978-0321925831
3rd edition
Authors: Norean Sharpe, Richard Veaux, Paul Velleman