Question 10.194

38. Miles per Gallon. The following data represent the combined (city and highway) fuel efficiency in miles per gallon (mpg) for independent random samples of models manufactured by Honda and Lexus.

Honda car mpg Lexus car mpg
Accord 24 GX 470 15
Odyssey 18 LS 460 18
Civic Hybrid 42 RX 350 19
Fit 31 IS 350 20
CR-V 23 GS 450 23
Ridgeline 17 IS 250 24
S2000 21
  1. The boxplots represent the miles per gallon for each manufacturer. Based on this graph, would you expect that the standard deviations of the two manufacturers are the same or different? Why?
  2. Note: Normal probability plots indicate that the normality assumption is not violated. Test whether the population standard deviations of the two manufacturers' fuel efficiency differ, using .
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