Question

A random variable X has the following probability distribution:

x	1	2	3	4	5	6	7
P(x)	k	2k	2k	3k	k2	2k2	7k2 + k

Determine P(X > 4)

Answer 1

P(X > 4)

= P(X = 5 or X = 6 or X = 7)

= P(X = 5) + P(X = 6) + P(X = 7)

= k² + 2k² + 7k² + k

= 10k² + k

= `10(1/10)^2 + (1)/(10)`

= `(1)/(10) + (1)/(10)`

= `(1)/(5)`