The table below gives a discrete probability distribution. x Pr{X = x} 17 19 21 23 25 27 29 31 0.191 0.1614 0.1366 0.1146 0.0974 0.0821 0.0688 0.0583 33 0.0487 35 0.0411 Calculate the theoretically exact standard deviation, o, for the distribution.