The Margin of Error and Other Sampling Issues:

1. Among other things, the Pew Research Center reported that 69% of a random sample of adult Americans said they use Facebook. As part of their survey results, the Pew Research Center mentioned that themargin of error for their survey was 2.9%. If you had to interpret the number 2.9% or explain to someone else what the margin of error tells us, what would you say?

2. There are 17,453 undergraduate students in the College of Arts and Sciences at OSU. Because the College is thinking about increasing its presence on Facebook, it would like to find out more about the percentage of its students who use Facebook regularly. A group of administrators surveys a random sample of n = 750 undergraduate students from the College of Arts and Sciences in order to learn more about their use of the Facebook. When asked if they regularly use Facebook, 88% of the sample says "yes." Use this information, along with what you learned in Chapter 3 about the quick and approximate method for the margin of error, to estimate the margin of error. Be sure to show your calculations below.

3. We often use a sample statistic and a margin of error to construct a confidence statement. what exactly is a confidence statement?

4. Use the information from Question 10 and the margin of error you estimated to write an appropriate 95% confidence statement. Remember the statement should have the following format: "I am 95% confident the interval from _____ to _____ includes __________________________________________________."

5. Would the margin of error change if a larger sample of students was surveyed? Please explain why or why not.

In Chapter 4, you learned about sampling errors and nonsampling errors. For each of the scenarios below, in Questions 14 through 16, indicate whether a sampling error or a nonsampling error is being described.If you feel what is being described is a nonsampling error, specify whether it is a response error or a nonresponse error.

6. The College of Arts and Sciences sends out surveys to a random sample of n = 1000 students, but only 750 of these students complete and return the surveys.

7. Instead of selecting their sample randomly, the College of Arts and Sciences decides to post information about their survey on Facebook and to wait for students to voluntarily respond to the survey.

8. Responses to certain survey questions are not accurate because the questions were misunderstood by students.