Find (By Inspection) the Expected Value and Standard Deviation of the Random

Short Answer

Find (by inspection) the expected value and standard deviation of the random variable with the following density function: $f ( x ) = \frac { 7 } { \sqrt { 2 \pi } } e ^ { - 49 / 2 ( x - 3.9 ) ^ { 2 } }$ Enter your answer as just two numbers (a real number to one decimal place followed by a reduced fraction) separated by a comma, the first representing E(X) and the second representing $\sqrt { \operatorname { Var } ( X ) }$ .