Question

A coin is tossed five times. Let X = the number of heads. Find P(X = 3).

Answer 1

Here, We Use Binomial Distribution

Therefore,.

The probability mass function of the binomial distribution is as follows:

.............................X = 0,1,2,3.........................n

Let X denote the "Number of Head Obtained"

We know that,

p = P(head obtained) = 1/2

Therefore,

q = 1-p = 1 - 1/2 = 1/2

The Random variable takes the value X = 0,1,2,3,4,5 and n = 5

Now, We find Out P(X = 3)

P(X = 3) =

P(X = 3) = 0.3125