Question

A random variable X has the following probability distribution:

X = x	0	1	2	3
P (X = x)	`1/10`	`1/2`	`1/5`	k

Then the value of k is

Options

• `1/4`

• `1/5`

• `2/5`

• `1/2`

Answer 1

`1/5`

Explanation:

Since `sum_(x = 0)^3`P(X = x) = 1,

`1/10 + 1/2 + 1/5 + "k" = 1`

`=> "k" + (1 + 5 + 2)/10 = 1`

`=> "k" = 1 - 4/5 = 1/5`