Q. 22 - The Practice of Statistics for AP

Question

In a poll, 

I. Some people refused to answer questions. 

II. People without telephones could not be in the sample. 

III. Some people never answered the phone in several calls. 

Which of these sources is included in the $\pm 2\%$ margin of error announced for the poll? 

(a) I only 

(b) II only 

(c) III only

(d) I, II, and III 

 (e) None of these  

Step-by-Step Solution

Answer

The option is (e).

Step 1: Given Information

Given in the question that, In a poll, 

I. Some people refused to answer questions. 

II. People without telephones could not be in the sample. 

III. Some people never answered the phone in several calls. 

Step 2: Explanation

The margin of error only contains sampling error.

I. Some people refused to answer questions is nonresponse bias, which is NOT a sampling error.

II. People without telephones could not be in the sample is called selection bias and this is NOT a sampling error.

III. Some people never answered the phone in several calls, which is called non-response bias, which is NOT a sampling error.