Probability Question

The following table summarizes the results of a poll taken of CEO’s and analysts concerning the economic impact of a pending piece of legislation: (Let’s read it like rows and colums since a table can’t be posted - please ask me if you don’t understand the question) CEO’s 40 30 70 Analysts 70 60 130 110 90 200 (Column 1 are the ones who : Think it will have a positive impact) (Column 2 are the ones who Think it will have a negative impact ) (Column 3 is just total of the observations - so is ROW 3) What is the probability that a randomly selected individual from this group will be either an analyst or someone who thinks this legislation will have a positive impact on the economy? (This is from SS2 Quants - Reading 8 and LOS e) I didnt really get the solution to this let’s see how you guys work it out and come up with a number I will post the answers later so you also get some practice TIA

(200-30) / 200

A- analyst is selected B- someone who thinks legislation will have +ve impact P(AUB) = P(A) + P(B) - P(A and B) = 130/200 + 110/200 - 70/200 =170/200

Perfect… I just found out that it was the reading error that I was doing it fault. Thanks