A resoarcher conducts a survey asking people to report the number of hours they spend using their phones each day. The researcher conducted this survey three
times. The mean and mean absolute deviation AD) for each trial are shown below.
Trial 1
Trial 2
Trial 3
Mean
2.5 hours
3.2 hours
2.1 hours
MAD
0.5 hours
0.2 hours
0.6 hours
Based on the data, which trial was most likely biased, and why?
Trial 3 because the mean is lowest.
Trial 3 because the MAD is highest.
Trial 2 because the MAD is at least 0.3
below the MAD of each other trial, and
this is larger than the MAD of Trial 2.
D
Trial 2 because the mean is at least 0.7 away from the mean of each other
trial, and this is larger than the MAD for each other trial.