mean deviation ##=0.2##

Compute mean ##barx##

##barx=(1.76+2.28+1.90)/3=1.98##

Mean deviation ##=(sum abs(x-barx))/n##

Mean deviation ##=(abs(1.76-1.98)+abs(2.28-1.98)+abs(1.90-1.98))/3##

Mean deviation ##=0.2##

God bless….I hope the explanation is useful.