Researchers polled 450 men. The poll found that 5196 of the men said they do not get enough time for themselves. The poll announced a margin of error of +3 percentage points. Describe
the number of men who said they do not get enough time for themselves according to this
survey
A high school has a policy that students' phones must be kept away during class. A principal
used the school roster to poll a random sample of 50 students, and only 10% said that they
ever had their phone out during class. The next day, the principal observed classrooms and
noticed that approximately 25% of students had their phone out at some point during class.
Which of these is the most concerning potential source of bias in the principal's poll?
a) Bias from undercoverage
b) Bias from using voluntary response
c) Response bias
d) Nonresponse bias