Question

Pollsters are concerned about declining levels of cooperation among persons contacted in surveys. A pollster contacts 99 people in the 18-21 age bracket and finds that 84 of them respond and 15 refuse to respond. When 276 people in the 22-29 age bracket are contacted, 257 respond and 19 refuse to respond. Assume that 1 of the 375 people is randomly selected. Find the probability of getting someone in the 18-21 age bracket or someone who agreed to respond.

Answer 1

Answer:

The probability of getting someone in the 18-21 age bracket or someone who agreed to respond $= 0.365$

Step-by-step explanation:

The counts are as follows  

Age Group  No of people contacted No of refusals      Total  

18-21               88                                  8                       96

22-29              240                                  42                       282

Total              328                                  50                       378

 

The probability of getting some one in the age bracket of 18-21 or some one who refused to respond is

$= \frac{96}{378} + \frac{50}{378} - \frac{8}{378} \\= \frac{96+50-8}{378} \\= \frac{138}{378} \\= 0.365$