Answer questions (a-d) for the following three data sets.
a= {3,5,7,9,11,12,12}
b= {1,2,2,5,5,9,13}
c= { 2,5,8,9,12,13,17}

a) find the mean of each data set
b) find the standard deviation of each data set
c) identify the data set with the largest and smallest standard deviation
d) explain what the standard deviations say about the data sets