2.The following 3x2 tables derived from the Nepal mortality data show mortality at 16 months of follow-up for different ages of girls in both treatment groups.

-> gender=Femaletrt= Placebo

Age of| Vital status

child|AliveDead |Total

-----------+----------------------+----------

< 1 |121969 |1288

|94.645.36 |100.00

-----------+----------------------+----------

1-2 |261572 |2687

|97.322.68 |100.00

-----------+----------------------+----------

3-4 |254225 |2567

|99.030.97 |100.00

-----------+----------------------+----------

Total |6376166 |6542

|97.462.54 |100.00

-> gender=Femaletrt=Vitamin A

Age of| Vital status

child|Alive Dead |Total

-----------+----------------------+----------

< 1 |129154 |1345

|95.994.01 | 100.00

-----------+----------------------+----------

1-2 |272452 |2776

|98.131.87 |100.00

-----------+----------------------+----------

3-4 |252915 |2544

|99.410.59 |100.00

-----------+----------------------+----------

Total |6544121 |6665

|98.181.82 |100.00

Suppose that 3 girls were randomly selected from the Vitamin A-treated group.Define the random variable of interest, X, as the number of out of the 3 who die during follow-up.

a)What are the possible outcomes (values) that may be observed for this random variable?

b)What is the probability that exactly one girl would die during follow-up?

c)What is the probability that exactly two girls would die during follow-up?

d)Describe the probability distribution for the number of deaths of Vitamin A-treated girls during 16 months of follow-up by filling in the table below:

Number of deaths (x)

P(X = x) = Prob of x deaths

0

1

2

3

Total

e)What probability distribution is this?What assumptions are made?

3.Refer back to the Vitamin A-treated girls.

a)What is the expected number of deaths in a 16-month period in a population of size 10?

b)Describe the Poisson probability distribution for the number of deaths of Vitamin A-treated girls during 16 months of follow-up by filling in the table below:

Number of deaths (x)

P(X = x) = Prob of x deaths

0

1

2

3

Total

c)Compare the probability distribution in 3 b) to the probability distribution in question 2 e).