There are 1000 voters and 200+ 250 support party A.
Originally Posted by yeoky
There are 1000 voters and 70+ 50 support party C.
C: The voter chosen supports Party C.
There are 1000 voters and 200+ 130+ 70 are male.
M: The voter chosen is a male
I have no idea what "(i)" and "(ii)" refer to.
You have determined the probability of A and M separately. Multiply them together. Now, from the chart, there are 1000 voters and 200 of them are men who support party A. Is that probability the same as the answer you got by multiplying?
Determine whether A and M are independent.
There are 200+ 250= 450 supporters of party A. 20% of 450 is 90. There are 130+ 300= 430 supporters of party B. 30% of 430 is 129. There are 70+ 50= 120 supporters of party C. 5% of 120 is 6. So there are a total of 90+ 129+ 6= 225 immigrant voters of whom 90 support party A.
(b) It is given that in the sample, 20% of Party A supporters, 30% of Party B supporters and 5% of Party C supporters are immigrants.
(i) One of the voters selected from the sample at random is an immigrant. What is the probability that this voter supports Party A?
Writing "C" for "immigrant voter who supports party C", "A" for "female voter who supports party A", and "B" for "neither one of those", we might have CBB, BCB, BBC, or ABB, BAB, BBA, or, ABC, ACB, BAC, BCA, CAB, CBA. You can find the probability of "A",
(ii) Three voters are chosen from the sample at random. Find the probability that there is exactly one immigrant voter who supports Party C or exactly one female who supports Party A (or both).
"B", or "C" separately and then find the probability of each of those 3 voter patterns.
Should the answer for part (b)(ii) be 0.4325370019 or 0.433683438?