1. Expected Value NounArithmetic Mean, Expectation, First Moment  
The sum of the values of a random variable divided by the number of values.  حسابی اوسط 
Statistics  a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the use of probability theory to estimate population parameters.  

Useful Words
Figure, Number  عدد / نمبر  the property possessed by a sum or total or indefinite quantity of units or individuals; "he had a number of chores to do".
Random  اتفاقی  lacking any definite plan or order or purpose; governed by or depending on chance; "a random choice".
Aggregate, Sum, Total, Totality  کل میزان  the whole amount.
Value  قدر  a numerical quantity measured or assigned or computed; "the value assigned was 16 milliseconds".
Variable  متنوع  a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity.