Question

A random variable X has the following probability distribution:

Values of X :	−2	−1	0	1	2	3
P (X) :	0.1	k	0.2	2k	0.3	k

 

Find the value of k. 

Answer 1

We know that the sum of probabilities in a probability distribution is always 1.

∴ P (X = -2) + P (X =-1) + P (X = 0) + P (X = 1) + P (X = 2) + P (X = 3) = 1

\[\Rightarrow 0 . 1 + k + 0 . 2 + 2k + 0 . 3 + k = 1\]

\[ \Rightarrow 4k + 0 . 6 = 1\]

\[ \Rightarrow k = \frac{0 . 4}{4} = 0 . 1\]