Bionomial Probability Distribution

[PARAJON]

I need help on this problem.. my answer that i get is the following for A, but I'm not sure. can you help me with a and b. thank you...;.


In a binomial situation n=5 and pie = .40 Determine the probabilities of the following events using the binomial formula.


a. x = 1
n = 5



P (x) = nCx x (1 - ) n - x


P (1) = 5!
1! (5-1)! 1 (.40) 1 (1-.40) 5-1

120 (.40) 1 (.60) 4

Answer 1.55184557





b. x = 2
n =5

 

[matt grime]

The probability of an event lies between 0 and 1. You've got 5 choose 1 as 5!1!, when it's 5, and the 1 and 4 should be powers you're raising 0.4 and 0.6 to.

If the probability of a success on trial is p (and q=1-p), then the probability of r successes in n trials is:

\binom{n}{r}p^rq^{n-r}

where

\binom{n}{r} = \frac{n!}{r!(n-r)!}

and is available as a button on your calculator