In Exercises 19-22, refer to the accompanying table, which describes results of
ID: 3176585 • Letter: I
Question
In Exercises 19-22, refer to the accompanying table, which describes results of roadworthiness tests of Ford Focus cars that are 3 years old (based on data from the Department of Transportation). The random variable x represents the number of cars that failed among six that were tested for roadworthiness. Using Probabilities for Unusual Events Find the probability of getting exactly three cars that fails among six cars tested. Find the probability of getting three or more cars that fail among six cars tested. Which probability is relevant for determining whether three is an unusually high number of failures among six cars tested: the result from part (a) or part (b)? Is three an unusually high number of failures? Why or why not?Explanation / Answer
a) P(exactly 3 cars fail among six cars) = 0.041
b) P(3 or more cars failing) = 0.041+0.005 = 0.046
c) Result from part (b)
d) There is no unsually high number of failures because the probability of more than 3 out cars failing is only 0.046. The average number of failures is 1x0.399+2x0.176+3x0.041+4x0.005 = 0.894. So, only less than 1 car fail out of 6 after 3 years and so, it cant be said that unusually high number of failure are there