AP EAMCET201824 Apr 2018Morning ShiftMathematicsProbabilityActual
The variance of the random variable X having the following distribution
Options
- A1 3
- B2 3
- C4 3
- D5 3
Correct answer
D. 5 3
Step-by-step solution
aligned & var (x)=E (x^2 )-[E(x)]^2 & aligned E(x) & = P_i x_i & = 1 6 (-2)+ 1 6 (-1)+ 1 3 0+ 1 6 (1)+ 1 6 (2) & =- 2 6 - 1 6 +0+ 1 6 + 2 6 =0 E (x^2 ) & = P_i x_i^2 & = 1 6 (-2)^2+ 1 6 (-1)^2+ 1 3 (0)^2+ 1 6 (1)^2+ 1 6 (2)^2 & = 4 6 + 1 6 +0+ 1 6 + 4 6 = 10 6 = 5 3 var (x) & = 5 3 -(0)^2= 5 3 . aligned aligned