Answer to Question #344071 in Statistics and Probability for Khadar

Question

9. A garage offers a breakdown recovery service for motorists that is available every day of the

year. According to their records the number of call-outs they received per day last year were:

Number of call-outs: 0 1 2 3 4

Number of days: 68 103 145 37 12

Required: What is the probability that

A. They receive two call-outs in a day?

B. They receive two or fewer call-outs in a day?

C. They receive one or more call-outs in a day?

D. They receive less than four call-outs in a day?

E. They receive more than two call-outs in a day?

Answer 1

There are 365 days in the year.

So,

A. $P(=2)=145/365=0.397$

B. $P(\le2)=P(=0)+P(=1)+P(=2)=68/365+103/365+145/365=0.866$

C. $P(\ge1)=1-P(=0)=1-68/365=0.814$

D. $P(<4)=1-P(=4)=1-12/365=0.967$

E. $P(>2)=P(=3)+P(=4)=37/365+12/365=0.134$