Refer to the Chapter 12 Buena School District bus data. Complete the following p
ID: 3366991 • Letter: R
Question
Refer to the Chapter 12 Buena School District bus data.
Complete the following problems:
1) Conduct a test of hypothesis to reveal whether the mean maintenance cost is equal for each of the bus manufacturers. Use the .06 significance level.
2) Conduct a test of hypothesis to determine whether the mean miles traveled is equal for each bus manufacturer. Use the .03 significance level.
3) Develop and interpret a 97% confidence interval for the disparity in the average maintenance cost between buses made by Bluebird and Thompson.
Show your work.
Here's the link with the excel file below.
http://www.mcneileconomics.com/uploads/8/1/3/9/8139463/_buena_chool_district_2010_v2.xlsx
Data Set 3--Buena School District Bus Data Miles Bus-Mfg 3 Bus Number MaintenanceAge Bluebird 853 883 822 329 Bluebird Bluebird 751 870 780 857 818 427 359 Gasoline 427 474 481 387 326 861 Bluebird Bluebird Bluebird Bluebird Thompson Bluebird Bluebird Bluebird Gasoline 422 433 474 558 561 357 329 497 459 355 15 838 760 741 859 826 12 19 490 370 Gasoline Gasoline Bluebird Bluebird Bluebird Bluebird Bluebird Bluebird 23 858 785 828 980 857 875 436 455 514 25 Gasoline 28 29 989 731 75 162 Bluebird 432 478 819 821 Bluebird 815 757 1008 831 849 839 812 471 751 Bluebird 493 452 358 833 692 Bluebird Thompson Bluebird 496 39 41 42 43 314 396 414 459 457 859 815 Thompson Thompson 45 398 570Explanation / Answer
Solution:
1. Null Hypothesis (Ho): µ1 = µ2 = µ3
Alternative Hypothesis (Ha): All population mean maintenance costs are not the same.
Using ANOVA: Single factor in DATA ANALYSIS in Excel
P-value = 0.005277
Since p-value is less than 0.06 significance level, we reject Ho.
Hence, we cannot conclude that the mean maintenance cost is equal for each of the bus manufacturers.
2.
Null Hypothesis (Ho): µ1 = µ2 = µ3
Alternative Hypothesis (Ha): All population mean miles travelled are not same.
P-value = 0.2415
Since p-value is greater than 0.03 significance level, we fail to reject Ho.
Hence, we cannot conclude that the mean miles traveled is equal for each bus manufacturer.
c.
97% confidence interval is given by:-
(441.8085 - 506.75) ± 2.491*sqrt(3016.767/47 + 2072.5/8)
-64.9415 ± 2.491*17.9791
-64.9415 ± 44.786
-109.727, -20.155
Anova: Single Factor SUMMARY Groups Count Sum Average Variance Column 1 47 20765 441.8085 3016.767 Column 2 25 11204 448.16 1892.39 Column 3 8 4054 506.75 2072.5 ANOVA Source of Variation SS df MS F P-value F crit Between Groups 28996.25 2 14498.13 5.618406 0.005277 3.115366 Within Groups 198696.1 77 2580.469 Total 227692.4 79