$1)$ A robot's end$-$effector position is measured to be $(2\mathrm{.}0,1\mathrm{.}0,0\mathrm{.}5)$ with a standard deviation of $0\mathrm{.}1$ mm in each direction. Calculate the repeatability of the robot.

$2)$Given a robot with positional accuracy of $+-0\mathrm{.}2$ mm $,$ what is the total possible error range for an end$-$effector target at $(100,50,25)mm?$

$3)$ Determine the calibration error if a robot's theoretical end$-$effector position is $(5,5,5)$ and the actual measured position is $(5\mathrm{.}1,4\mathrm{.}9,5\mathrm{.}2).$