Question 1:

A. Find the following probabilities for a standard normal variable, Z

1) P(Z<-1.27)

2) P(-2.03

3) P(Z>1.74)

4) P(Z<0.17)

B. Find z if we know that the area to the left of z (under the normal curve) is 0.9265.

C. The weekly sales of a store follow the normal distribution with a mean of 3000

euros and standard deviation 350 euros. What is the probability that the weekly sales

are higher than 2800 euros?

caller (5).

Question 2:

The probability distribution for the number of credit cards owned is given below:

Number of cards

Probability

0.06 1 0.31 2 0.28 3 0.15 0.12 4 0.08

a) Show that the above table is a valid probability distribution.

b) What is the probability that a randomly selected person has less than 3 credit cards?

c) What is the "expected value" of the number of credit cards owned by a random

person?