Omar recorded the number of hours he worked each week for a year. Below is a random sample that he took from his data.


13, 17, 9, 21


What is the standard deviation for the data?


Standard deviation: s = StartRoot StartFraction (x 1 minus x overbar) squared + (x 2 minus x overbar) squared + ellipsis + (x n minus x overbar) squared Over n minus 1 EndFraction EndRoot.


A.) 0

B.) 4

C) 2

D.) 26.7