0 votes 0 votes The expected value of a probability function, when probability is measured on a scale of 0 to 1, coincides with it's (a) Mean (b) Variance (c) Standard deviation (d) None of them Probability probability + – Prajna asked Apr 9, 2019 Prajna 435 views answer comment Share Follow See all 4 Comments See all 4 4 Comments reply ankitgupta.1729 commented Apr 9, 2019 reply Follow Share expected value and mean both are same (mostly). So, I think answer should be (a) and term 'expectation' is used for random variables, not for probability function.. 0 votes 0 votes srestha commented Apr 9, 2019 reply Follow Share @ankitgupta.1729 why not s.d.? 0 votes 0 votes ankitgupta.1729 commented Apr 10, 2019 reply Follow Share mam, expectation gives weighted sum. Suppose, you have sample input as $1,1,1,1,3,3,5,5,5$ then expected value will be $1*\frac{4}{8} + 3*\frac{2}{8} + 5*\frac{3}{8}$ which is also a mean. Now, Suppose, random variable is $X$ Then Standard Deviation(X) = $\sqrt{Var(X)}$ = $\sqrt{E(X^{2})-[E(X)]^{2}}$ which is not equal to E(X) or mean generally. 0 votes 0 votes Prajna commented Apr 10, 2019 reply Follow Share when probability is measured on a scale of 0 to 1, coincides with it's....... i'm not understanding what it means ..... 0 votes 0 votes Please log in or register to add a comment.