Question 52671
		Men	Women	Total
In Favor	1,400	   280	1,680
Opposed	   840	3,080	3,920
Total	2,240	3,360	5,600

	 

	Let:	M be the event a resident is a man
		W be the event a resident is a woman
		F be the event a resident is in favor
		P be the event a resident is opposed


	a.	Find the joint probability table.
Need figure prob of M&F, W&F, M&O, W&O
For example P(M&F)=1400/5600=0.25
	b.	Find the marginal probabilities.
Nee figure Prob of M, of W, of F, or O
For example P(M)=3920/5600=0.70 
	c.	What is the probability that a randomly selected resident is a man and is in favor of building the bridge?
Prob(M&F)= 0.25 as we figured above
	d.	What is the probability that a randomly selected resident is a man?
P(M)=3920/5600=0.70
	e.	What is the probability that a randomly selected resident is in favor of building the bridge?
P(F)=1680/5600=0.30
	f.	What is the probability that a randomly selected resident is a man or in favor of building the bridge?
P(M or F)= P(M)+P(F)-P(M&f)= [3920+1680-1400]/5600=4200/5600=0.75
	g.	A randomly selected resident turns out to be male.  Compute the probability that he is in favor of building the bridge.
P(F|M)= 1400/2240=0.625

Cheers,
Stan H.