Reference no: EM1312112
Q1) In Dallas, a few fire trucks were painted yellow (instead of red) to increase their visibility. In a test period, fleet of red fire trucks made 153,348 runs and had 20 accidents, whereas fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At α = .01, did yellow fire trucks have a considerably lower accident rate?
(a) Define the hypotheses.
(b) Define the decision rule and sketch it.
(c) Determine sample proportions and z test statistic.
(d) Make a decision.
(e) Determine the p-value and interpret it.
(f) If statistically important, do you believe difference is large sufficient to be significant? If so, to whom, and explain why?
g) Is normality assumption fulfilled? Describe.
Accident Rate for Dallas Fire Trucks
Statistic Red Fire Trucks Yellow Fire Trucks
Number of accidents x1 = 20 accidents x2 = 4 accidents
Number of fire runs n1 = 153,348 runs n2 = 135,035 runs