True about Standard Deviation Curve

(A) Mean = Median# STANDARD DEVIATION:> The standard deviation is the most frequently used measure of deviation. In simple terms, it is defined as 'Root -Means - Square- Deviation'.> SD is the "average" degree to which scores deviate from the mean.> More precisely, you measure how far all your measurements are from the mean, square each one, and add them all up. The result is called the variance.> Take the square root of the variance, and you have the standard deviation.