A sample of 15 data is as follows: 17, 18, 17, 17, 13, 18, 5, 5, 6, 7, 8, 9, 20, 17, 3. The mode of the data is A. 4 B. 13 C. 17 D. 20

The mode is the most frequent number in a set of data. In this case, the mode is 17, because it appears 4 times in the data set. The other numbers appear only once or twice.

A. 4 is not the mode, because it only appears once in the data set.
B. 13 is not the mode, because it only appears twice in the data set.
C. 17 is the mode, because it appears 4 times in the data set.
D. 20 is not the mode, because it only appears once in the data set.