Question

Is the mean and mean deviation the same❓❔

Answer 1

No.
The mean is the quotient of the sum of a set of values and the number of these values.
The mean deviation is the mean of the absolute deviations of a set of values. And the absolute deviation is the absolute value of the difference of a value and its mean.

Symbolically:
Mean:
`\overline{x}=(1)/(n)\sum_(i=1)^nx_i`
Mean deviation:
`MD=(1)/(n)\sum_(i=1)^n|x_i-\overline{x}|`