Issue 1

Give the probability distribution of the number of daughters in families of:

a) 3 children

b) 4 children

Issue 2

An umbrella dealer can earn $300 a day when it rains. He can lose $60 a day when it's sunny. What amount can he expect to earn on average per day if the probability that he rain is 0.3? (Here we seek to determine the expectation E(X) which corresponds to the mean value of the distribution probabilities.)

Issue 3

Find the probability that in a family of 4 children, there is at least 1 boy. We assume that the probability of the birth of a boy = the probability of the birth of a girl. Issue 4 Out of 2000 families with 4 children, how many should have on average: a) at least 1 boy b) 2 boys c) 1 or 2 daughters d) no daughter?

Issue 5

You are conducting a survey on the alcohol consumption habits of Quebecers aged 16 to 45 years old. You divide the population into three age groups:

16-25 years old

26-35 years old

36-45 years old.

We know that the Quebec population is made up of:

18% aged 16-25

45% aged 26-35

37% aged 36-45.

We also know that:

57.5% of 16-25 year olds consume alcohol at least once a week

59.6% of 26-35 year olds consume alcohol at least once a week

49.4% of 36-45 year olds consume alcohol at least once a week.

A person is chosen at random from the population. We know that this person consumes alcohol at least once a week. What is the probability that this person is in the 36-45 age group?