167. Insurance companies A and B each earn an annual profit that is normally distributed with
the same positive mean.The standard deviation of company A’s annual profit is one half
of its mean.
In a given year, the probability that company B has a loss (negative profit) is 0.9 times
the probability that company A has a loss.
Calculate the ratio of the standard deviation of company B’s annual profit to the standard
deviation of company A’s annual profit.
(A) 0.49
(B) 0.90
(C) 0.98
(D) 1.11
(E) 1.71