Which survey is biased?

a. going to the mall and asking people what their favorite color is.

b. going to the mall and asking people what their favorite place to shop is.

c. going to the mall and asking people what television channel they watch most.

d. going to the mall and asking people what radio station they listen to most often.

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. the design of the study justifies the assumption that the sample can be treated as a simple random sample. use the data to construct a 99% confidence interval estimate of μ, the mean duration of game play. 4028 4316 4816 4650 4036 5010 4833 4331 4307