People love living in California for many reasons, but traffic isn’t one of them. Based on a random sample of 572 employed California adults, a 90% confidence interval for the average travel time to work for all employed California adults is 23 minutes to 26 minutes.

a. Interpret the confidence level.

b. Name two things you could do to reduce the margin of error. What drawbacks do these actions have?

c. Describe how nonresponse might lead to bias in this survey. Does the stated margin of error account for this possible bias?