1 votes 1 votes Suppose the random variable X has the probability distribution given below: X -2 -1 0 1 2 P(X=X) 0.25 0.20 0.15 0.35 0.05 Let $Y=(2*(X^2))+6$.The expected value E(Y) is: A) 9.5 B) 6. C )15.5. D )18 Probability random-variable probability + – Gaurangi Katiyar asked Nov 8, 2018 edited Nov 8, 2018 by Mk Utkarsh Gaurangi Katiyar 760 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 0 votes 0 votes $Y = 2(X^2) + 6 $ if X = 2 or X = -2 $\rightarrow$ Y = 14 X = 1 or X = -1 $\rightarrow$ Y = 8 X = 0 , Y$\rightarrow$ 6 $P(14) = 0.25 + 0.05 = 0.30$ $P(8) = 0.20+0.35 = 0.55$ $P(6) = 0.15$ $E(Y) = 14 \times 0.30 + 8 \times 0.55 + 6 \times 0.15 = 9.5$ Mk Utkarsh answered Nov 8, 2018 selected Nov 8, 2018 by Gaurangi Katiyar Mk Utkarsh comment Share Follow See all 3 Comments See all 3 3 Comments reply Gaurangi Katiyar commented Nov 8, 2018 reply Follow Share Thank you sir 0 votes 0 votes Mayankprakash commented Nov 9, 2018 reply Follow Share @ Utkarsh Can you please explain how to attempt these type of problems and why are putting x = 0,1,2,-2? How E(y) = 14 * 0.30 +8 *0.5 + 6? I'm not able to understand.please help Thanks 0 votes 0 votes Mk Utkarsh commented Nov 9, 2018 reply Follow Share Mayankprakash This question is just asking for basics of random variable. Y is a dependent random variable which depends on value of X. So by substituting the value of X you can calculate value of Y and E(Y) is expectation(mean) of random variable Y. 0 votes 0 votes Please log in or register to add a comment.