Statistics Probability question!

I need help with this question!!

Suppose that 4% of all adults suffer from diabetes and that 28% of all adults are obese. Suppose also that 2% of all adults both are obese and suffer from diabetes.

(a) Find the probability that a randomly chosen adult who is obese also suffers from diabetes. Round your answer to 2 decimal places.
(b) Find the probability that a randomly chosen adult is obese, given that he or she suffers from diabetes. Round your answer to 2 decimal places.

zolton5971 said:

I need help with this question!!

Suppose that 4% of all adults suffer from diabetes and that 28% of all adults are obese. Suppose also that 2% of all adults both are obese and suffer from diabetes.

(a) Find the probability that a randomly chosen adult who is obese also suffers from diabetes. Round your answer to 2 decimal places.
(b) Find the probability that a randomly chosen adult is obese, given that he or she suffers from diabetes. Round your answer to 2 decimal places.

Click to expand...

You should know the formulas. But, if you don't, work out the problem. For example:
9% of apples are grannies.
12% of apples are yellow.
3% of apples are both grannies and yellow.

1000 apples
90 are grannies
120 are yellow
30 are yellow grannies
(a) Find the probability that a randomly chosen yellow apple is a grannie.
Now there will be a total of 120 yellow apples and there are 30 yellow grannies so the probability of getting a randomly chosen yellow apple which is a grannie = 30/120=0.25
= (30/1000)/(120/1000)
That is P(A given B) = P(A and B)/P(B)
(b) Find the probability that a randomly chosen apple is yellow, given that is a grannie.
If the apple is a grannie there are 90 of them and there are 30 yellow grannies so there probability that an apple is yellow given that it is a grannie = 30/90=0.33 to two decimal places which is the same formula but different A and B

EDIT: Every time a probability (or sadistics) question comes up I have to be extra careful. Well, I wasn't this time but I did correct it (I hope).

Okay so is this correct?
4%
28%
2%

say 100 total people
4
28
2
2/28=0.07
=(2/100)/(28/100) =.02/.28=.07


A.=.07

B. 2/4=.5

zolton5971 said:

Okay so is this correct?
4%
28%
2%

say 100 total people
4
28
2
2/28=0.07
=(2/100)/(28/100) =.02/.28=.07


A.=.07

B. 2/4=.5

Click to expand...

Looks fine. Good job!