Question

If there is a 20% probability of rain for each of the next 7 days, what is the probability that it will rain on exactly 1 of the next 7 days?

Answer 1

This is binomial distributed with parameters n=7 and p=0.2

Answer 2

.37 .63 .5 0r .43

Answer 3

Well, there's a formula that comes with the binomial distribution: \[P(X=x)=\left(\begin{matrix}n \\ c\end{matrix}\right)p^{x}(1-p)^(n-x)\]
I'm sure you can fill all the values in?

Answer 4

Thank you

Answer 5

what woud x be

Answer 6

1

Answer 7

The amount of the days it rains.

Answer 8

The latex failed there, so here's pretty typography for the formula:
http://www.wolframalpha.com/input/?i=binomial+distribution+pdf

Answer 9

oh alright that makes more sence