10.30: In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. Duringa test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet ofyellow fire trucks made 135,035 runs and had 4 accidents. At α = .01, did the yellow fire truckshave a significantly lower accident rate? (a) State the hypotheses. (b) State the decision rule andsketch it. (c) Find the sample proportions and z test statistic. (d) Make a decision. (e) Find thep-value and interpret it. (f ) If statistically significant, do you think the difference is large enough tobe important? If so, to whom, and why? (g) Is the normality assumption fulfilled? Explain.Source: The Wall Street Journal, June 26, 1995, p. B1.Accident Rate for Dallas Fire TrucksStatistic Red Fire Trucks Yellow Fire TrucksNumber of accidents x1 = 20 accidents x2 = 4 accidentsNumber of fire runs n1 = 153,348 runs n2 = 135,035 runsANSWER:a). Did the yellow firetrucks have a lower......
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