You Have Arranged to Go Camping for Two Days in March.You

Multiple Choice

You have arranged to go camping for two days in March.You believe that the probability that it will rain on the first day is 0.4.If it rains on the first day,the probability that it also rains on the second day is 0.5.If it doesn't rain on the first day,the probability that it rains on the second day is 0.3.Let the random variable X be the number of rainy days during your camping trip.Find the standard deviation of X.

A) σ = 0.67
B) σ = 0.76
C) σ = 0.57
D) σ = 0.77
E) σ = 0.70