Question

QUESTION 3

A class wrote two Mathematics tests. 72% of the class

passed both tests and 90% of the class passed the first test.

A student is chosen at random from this class. What is the probability that the student passed the second test given

that the student passed the first test?

QUESTION 4

The mean number of cars confiscated by a wrecker is five per day. Using the

Poisson distribution,

a) find the probability of the number of cars confiscated on any given day is

exactly 5

b) At most 3

c) More than 3

QUESTION 5

A bus company advertised a mean time of 150 minutes for a

trip between two cities. A consumer group had reason to

believe that the mean time was more than 150 minutes. A

sample of 40 trips showed a mean ˉx=153 minutes and a

standard deviation s=7.5 minutes. At the 0 .05 level of

significance, test the consumer group’s belief.

Answer 1

Solution : Given that p both tests) = 72% p (first test) = 90%. Assume that number of samples ne 100 pboth tests) = 12 P (first test) = 90 p (second o first) P[second I first) P (First ) 72 90 Oo8 In percentage p second l first.) -0.88100 =1801°%