Twelve randomly-chosen students were asked how many times they had missed class during a certain semester, with this result: 2, 1, 5, 1, 1, 3, 4, 3, 1, 1, 5, 18. For this sample, the standard deviation is approximately _____.
A. 3.75 B. 4.55 C. 4.75 D. 3.03
Twelve randomly-chosen students were asked how many times they had missed class during