statistics Chapter 14-15

Question

Polling, part II. According to Pew Research, the contact rate (probability of contacting a selected household) in 1997 was 69% and in 2003 was 76%. However, the cooperation rate (probability of someone in the contacted household agreeing to be interviewed) was 58% in 1997 and dropped to 38% in 2003.

1. What is the probability (in 2003) of obtaining an interview with the next household on the sample list? (To obtain an interview, an interviewer must both contact the household and then get an agreement for the interview.)

 

1. Was it more likely to obtain an interview from a randomly selected household in 1997 or in 2003?

Answer 1

Hi Minahil,

1) We have two rates that we need to focus on for this problem: the contact rate in 2003 and the cooperation rate in 2003.

So the probability (in 2003) of obtaining an interview with the next household on the sample list will be:

P = 0.76 * 0.38 = 0.288 = 29 percent

2) Here, we must first find the probability of randomly contacting a selected household and the chances of them agreeing to be interviewed.

P = 0.69 * 0.58 = 0.4002 = 40 percent

This statistic compared to the answer we have in number 1 tells us that it was more likely to obtain an interview from a randomly selected household in 1997 rather in 2003. In 2003, the chances were 29 percent, which is a 11 percent drop from 40 percent.

Hope this helps! Have a good day!