# Math Help - joint pmf question: URGENT

1. ## joint pmf question: URGENT

Hi, I have a statistics question.

Q. in the country of lalala the labour force is 1,000,000. half of this labour is men and half women. The joint frequency table of the labour force by gender and weekly hours worked is as follows.

-----|men (000s) | women (000s)
0h - | --- 60 ---- | ----50
20h -|---110 ---- | ----200
40h -|--- 330 ---- | ---- 250

let the random variable X be such that

X=0 for men
X=1 for women

And the random variable Y:

Y=weekly hours worked

i) specify the joint pmf of X and Y
ii) specify the marginal pmfs of X and Y
iii) find all distinct conditional pmf's of Y, conditional upon X
iv) find the conditional expectation function of Y, conditional upon X
v) find the covarianc between X and Y
vi) in light of the analysis, would you agree that "Men are clearly more likely to work than women"

Above is the question.

I am able to solve simpler question where the joint frequency table is 2x2. But this one is obviously 2X3 and I am very confused ! Please help.

2. Originally Posted by secondary
Hi, I have a statistics question.

Q. in the country of lalala the labour force is 1,000,000. half of this labour is men and half women. The joint frequency table of the labour force by gender and weekly hours worked is as follows.

-----|men (000s) | women (000s)
0h - | --- 60 ---- | ----50
20h -|---110 ---- | ----200
40h -|--- 330 ---- | ---- 250

let the random variable X be such that

X=0 for men
X=1 for women

And the random variable Y:

Y=weekly hours worked

i) specify the joint pmf of X and Y
ii) specify the marginal pmfs of X and Y
iii) find all distinct conditional pmf's of Y, conditional upon X
iv) find the conditional expectation function of Y, conditional upon X
v) find the covarianc between X and Y
vi) in light of the analysis, would you agree that "Men are clearly more likely to work than women"

Above is the question.

I am able to solve simpler question where the joint frequency table is 2x2. But this one is obviously 2X3 and I am very confused ! Please help.
Wellthe pmf is

Code:
             X
0      1
0   0.06   0.05
Y  20   0.11   0.20
40   0.33   0.25
RonL