Answer:
0.06166
sd = 0.9447
Explanation:
probability of having a wet day on any given day at 15 percent = 0.15 is as follows
Lets define X as the number of days that it is going to rain.
we have x binomial (7, 0.15)
probability(x = 3) = (7 3)p³(1-p)⁴
we have 7!/3!4!(0.15)³(0.85)⁴
= (210/6)*0.003375*0.522
= 35*0.003375*0.522
= 0.06166 approximately 0.0617
b standard deviation = [tex]\sqrt{np(1-p)}[/tex]
= [tex]\sqrt{7*0.15(0.85)}[/tex]
= [tex]\sqrt{0.8925}[/tex]
= [tex]0.9447[/tex]