# Finding Standard Deviation in a binomial distribution : Help Please

#### MNR

##### New Member
Hello,
I am trying to find the mean and standard deviation of a binomial distribution.
A basket ball player has the following probability for success in two shot free throws.
P(0) is 0.16,
P(1) is 0.48
P (2) is 0.36

I need to find the mean and std deviation.
I get the mean correctly as 1.2, but not able to get the std. deviation of the given answer of 0.69. Requesting guidance

#### Dason

If you can calculate the expected value can you figure out the success probability (p)?

#### Con-Tester

##### Member

Note that you can determine P, the probability of a success on any single throw, from the information given. In fact, more information was given than is strictly necessary: You know that it's a binomial distribution (a throw either succeeds or fails), and that n = 2 (two throws), so you only need any one of the three probabilities given to determine P.

Once you have P, it's a simple matter of plugging the values into the formulae for μ and σ.