Question

1. The heights of an adult females are normally distributed with a mean of 150 cm and standard deviation of 8 cm. Let X be the height of an adult females;

1. Find PX ≤ 160               

2. Find P140<X<170

2. A telemarketer is a person who makes phone calls to prospective customers to promote sales of company’s products or services. The probability of a telemarketer in AZA Boutique Design in making a sale on a customer call is 0.2. Let X be the number of sale.

1. Find the probability that no sales are made in 5 calls.  

                                                  

2. If the manager of the company wanted an average of 3 sales in a day, find the number of calls that should be made by a telemarketer in order to achieve the target.

3. Patients arrived at hospital emergency department follows a Poisson distribution with a mean of 4 patients per hour.

1. In any 90 minutes period of time, find the probability that exactly 10 patients arrived.                                                            

2. Find the standard deviation of the number of patients arriving at the hospital.

Answer 1

1. Let X be the height of an adult females in centimetre.

Therefore,

I.

.

### by using z table.

ii.

by using z table