1. A charter high school surveyed its alumni, from a list it maintains for fundraising purposes, to find out how well they were doing in the job market. Nearly 50 percent responded, and the survey showed that 90 percent of alumni had full-time jobs. Do you think that this estimate is biased? How would the propensity to be covered by the list and the propensity to respond to the survey likely bias the estimate?

2. Internet commerce has become vital to the modern economy, yet it remains vulnerable because customers fear internet fraud and identity theft. But how afraid are we, really? A telephone survey of an RDD sample of 1,000 U.S. adults found that fully 38 percent did not trust online payments, banks, and other e-commerce providers. Based on what you have read in this chapter about coverage and nonresponse in telephone surveys, how might this estimate be biased?

3. ) Say you are a principal of a school and want to learn how well parents feel the school communicates with them. You send home a survey with students and then have each teacher follow up with a phone call to parents about how important the survey is.What kind of non-response problem will you have? What bias do you think would result in your measure of school communication? Explain using a path diagram showing the propensity to respond.