Answer to Question #340249 in Statistics and Probability for jazzy

Question

Pollsters are concerned about declining levels of cooperation among persons contacted in surveys. A pollster contacts 97 people in the 18-21 age bracket and finds that 82 of them respond and 15 refuse to respond. When 260 people in the 22-29 age bracket are contacted, 240 respond and 20 refuse to respond. Assume that 1 of the 357 people is randomly selected. Find the probability of getting someone in the 22-29 age bracket or someone who refused to respond.

Report the answer as a percent rounded to one decimal place accuracy. You need not enter the "%" symbol.

P(22-29 or refused) =

Answer 1

We want to know how many people are in the 22-29 age bracket or refused to respond, so we will accept anyone who falls into at least one of these categories. There are 260 people aged 22-29, plus another 15 who refused to respond from the other age group. That total of 260 + 15 = 275 people is our numerator, out of 357 people so we get:

275 / 357 = 77 percent.