help with probability in math...?

Question

the directions say: A and B are independent events. Find the missing probability.

P(A)=3/7, P(A and B)=1/3. Find P(B)

i have no clue how to do this so can u explain it so i can finish the rest of them..thx :)

Answer 1

Directly from a math text:

With independent events, the probability of A and B happening together is the product of the two events. So P(a) multiplied by P(b) = P (a and B)

3/7 * X = 1/3

Solve for x.

Answer 2

P(A and B) means you multiply the prob of A and the prob of B to get the Probability of A and B. Now, if P(A) = 3/7 and P(A and B) = 1/3, then we have to find the following:

3/7 times what gives you 1/3

algebraically:

(3/7)x = (1/3) solve for x
multiply both sides times the reciprocal of 3/7 which is 7/3

(7/3) (3/7)x = (1/3)(7/3)

7/3 times 3/7 cancel out, 1/3 times 7/3 is 7/9

x = 7/9

so, P(B) is 7/9

Answer 3

"And" means "times" in probability.
For independent events P(A and B) = P(A) * P(B).
So ... 1/3 = 3/7 * P(B)
To solve this divide by 3/7, which is the same as multiplying by 7/3.
The answer is 7/9 = P(B).

Answer 4

well if you know a then just plug it in


3/7+b=1/3 then jsut subtract 3/7 from 1/3

then find the coment denominated of the 7 and 3 witch is what think about it 21
so what you do is

9/21+7/21=b

so b = 16/21 so do you think you can lower the fraction to the lowest denominater

i say no so bc =16/21

Answer 5

probability of A and B = probability of A times the probability of B, so:

P(A) * P(B) = P(A and B)
3/7 * P(B) = 1/3
P(B) = 1/3 * 7/3 = 7/9

Hope this helps!

Answer 6

go to www.studybuddy.com and you can find almost all answers. Good Luck.