Using the sample formulas, find the mean, variance, and standard deviation for the grouped data displayed in the following table. X 0 to less than 4 18 4 to less than 8 22 8 to less than 12 16 12 to less than 16 12 16 to less than 20 7 20 to less than 24 5 Carry out all calculations exactly, round to 2 decimal places the final answers only