Davina selected 50 people at random and asked them whether they had watched the documentary on antarctica on television the previous night. she repeated this survey using the same method three more times.
do any of the surveys appear to be biased?
watched antarctica documentary last night? survey
1 2 3 4
yes 13 14 35 17
no 37 36 15 13
a.
yes, because all four surveys do not have identical results.
b.
yes, because the results from survey 3 differ significantly from the other surveys’ results.
c.
no, because davina surveyed the same number of people each of the four times.
d.
no, because all four surveys have about the same number of people saying “yes” and about the same number of people saying “no.”