Question

A city of Punjab has a 15 percent chance of wet weather on any given day. What is the probability that it will take a week for it three wet weather on 3 separate days? Also find its Standard Deviation

Answer 1

0.06166

sd = 0.9447

Step-by-step 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 =
`√(np(1-p))`

=
`√(7*0.15(0.85))`

=
`√(0.8925)`

=
`0.9447`