The probability function of a discrete random variable X is given by p(x)=x^2 x =1,2,3. Find E(X)

The expectation of x, E(X), is the sum of the product of the value of the ith outcome (xi) and the probability of the ith outcome (pi). So:

E(X)=1+(42)+(93)=36

TM

Related Maths A Level answers

All answers ▸

The straight line with equation y = 3x – 7 does not cross or touch the curve with equation y = 2px^2 – 6px + 4p, where p is a constant. Show that 4p^2 – 20p + 9 < 0.


Find the first three terms of the binomial expansion of (3 + 6x)^(1/2).


How do I use the chain rule for differentiation?


Solve the simultaneous equations: x^2 + 8x + y^2; x - y = 10.