You are part of a team investigating the identifying motorvehicle accidents. A multiple regression model is to be constructedto predict the number of motor vehicle accidents in a town per yearbased upon the population of the town, the number of recordedtraffic offenses per year and the average annual temperature in thetown.
Data has been collected on 30 randomly selected towns:
Number of motor vehicle accidents per year | Population (× 1000) | No. of recorded traffic offences (× 100) | Average temperature °F |
---|
355 | 181 | 29 | 78 |
490 | 257 | 56 | 82 |
597 | 441 | 34 | 81 |
475 | 50 | 95 | 81 |
922 | 495 | 102 | 82 |
736 | 38 | 165 | 81 |
305 | 167 | 25 | 84 |
1,128 | 378 | 191 | 78 |
745 | 369 | 86 | 76 |
476 | 237 | 63 | 84 |
143 | 100 | 4 | 84 |
203 | 118 | 21 | 79 |
909 | 489 | 106 | 78 |
410 | 210 | 39 | 77 |
642 | 138 | 131 | 81 |
847 | 308 | 138 | 82 |
604 | 418 | 40 | 77 |
719 | 194 | 132 | 78 |
350 | 319 | 8 | 84 |
327 | 70 | 61 | 76 |
1,038 | 259 | 192 | 78 |
756 | 299 | 115 | 81 |
635 | 440 | 40 | 79 |
796 | 283 | 131 | 85 |
301 | 64 | 56 | 81 |
135 | 26 | 26 | 79 |
639 | 31 | 150 | 81 |
325 | 210 | 13 | 77 |
441 | 43 | 98 | 79 |
522 | 370 | 26 | 82 |
a)Find the multiple regression equation using all threeexplanatory variables. Assume that X1 is population,X2 is number of recorded traffic offenses per year andX3 is average annual temperature. Give your answers to 3decimal places.
y^ = + population + no. traffic offences + averagetemp
b)At a level of significance of 0.05, the result of the F testfor this model is that the null hypothesis isis not rejected.
For parts c) and d), using the data, separately calculate thecorrelations between the response variable and each of the threeexplanatory variables.
c)The explanatory variable that is most correlated with numberof motor vehicle accidents per year is:
population
number of traffic offenses
average annual temperature
d)The explanatory variable that is least correlated with numberof motor vehicle accidents per year is:
population
number of traffic offenses
average annual temperature
e)The value of R2 for this model, to 2 decimalplaces, is equal to
f)The value of se for this model, to 3 decimalplaces, is equal to
g)Construct a new multiple regression model by removing thevariable average annual temperature. Give your answers to 3 decimalplaces.
The new regression model equation is:
y^ = + population + no. traffic offences
h)In the new model compared to the previous one, the value ofR2 (to 2 decimal places) is:
increased
decreased
unchanged
i)In the new model compared to the previous one, the value ofse (to 3 decimal places) is:
increased
decreased
unchanged