The table shows the number of practice problems completed in 30 minutes in three samples of 10 randomly
selected math students.
Number of practice problema completed in 30 minutes
Sample 1 12 13 11 10 11 13 12 13 9 13 Mean = 11.7
Sample 2 13 18 17 14 15 14 18 14 15 16 Mean = 15.4
Sample 3 18 14 16 15 16 14 17 16 15 14 Mean = 15.5
Which statement is most accurate based on the data?
O A. A prediction based on the data is not completely reliable, because
the mean of sample 1 is noticeably lower than the means of the
other two samples
OB. A prediction based on the data is not completely reliable, because
the means of samples 2 and 3 are too close together.
OC. A prediction based on the data is reliable, because the means of
samples 2 and 3 are very close together
O D. A prediction based on the data is reliable, because there are no
noticeable differences among the samples.