00:01
Alright, so first we're going to let x be the number of men who had both cancer and smoked cigars.
00:06
And the number of men who either had cancer or smoked cigars or both is 3 ,000 minus 2 ,655, which is 345.
00:18
And using the principle of inclusion and exclusion, we know 240 plus 270 minus x equals 340, which will give us that x is 165.
00:31
Then we can calculate the number of men who had cancer but did not smoke cigars.
00:38
Men who had cancer but did not smoke cigars is 75 and men who smoked cigars but did have cancer is 105.
00:47
Then we can fill in the probability table and compute the probability that the man chosen has had cancer or does or smoked cigars.
01:02
This is going to be 240 over 3 ,000 plus 270 over 3 ,000 minus 165 over 30 ,000.
01:15
And this will give us 0 .1150...