The scheduling manager of an electricity supply company knows that the number of emergency calls follows a Poisson distribution with an average of 7 calls per week (7 days)

i. What is the probability that the company will receive exactly 2 emergency calls during a specified week?

A 0.030 B 0.970 C 0.023 D 0.993

ii. What is the probability that there will be at least four emergency calls on a given day?

A 0.173 B 0.918 C 0.996 D 0.019

Question 2

uppose that weekly household expenditures on petrol are normally distributed, with a mean of $120 and a standard deviation of $50.

i. A family is randomly selected. Find the probability that this family spends more than $245 per week on petrol?

A 2.5 B 0.0062 C 0.9938 D 0.0202

ii. The government wants to promote public transport and will award a prize to the families who spend the lowest amount on petrol. If the government only wants to give a prize to 10% of households, what is the most that a family is allowed to spend on petrol each week to obtain the prize?

A $56 B $184 C $3.50 D $217.60

iii. In a sample of 25 families, what is the probability that the average weekly expenditure on petrol will be less than $105?

A 0.0668 B 0.9332 C 0.3821 D 0.6179