Calculate the mean, the variance, and the standard deviation of the following discrete probability distribution. (Negative values should be indicated by a minus sign. Round intermediate calculations to at least 4 decimal places. Round your final answers to 2 decimal places.) P(X = x) -39 0.56 -20 0.22 -9 0.16 -6 0.06 Mean Variance Standard deviation -17.90 47.09 6.86