For a life currently age 90, you are given l90 = 100,000 and the following extract from a mortality table: k d90 k 0 8,000 1 10,000 2 14,000 3 18,000 4 23,000 5 27,000 Calculate the variance of k
a) 4.93
b) 5.52
c) 6.21
d) 7.10