Identify the variance and the standard deviation of the given data set.
{ 4,6,8,12,15,17,10,24 }
a. variance: 12.2 standard deviation: 6.1
b. variance: 6.1 standard deviation: 37.25
c. variance: 37.25 standard deviation: 12.2
d. variance: 37.25 standard deviation: 6.1