2. The relative frequency distribution of the number of TVs sold in a day in a department store in the last year is as follows: For the numbers of TV sold of 0, 1, 2, 3, and 4, the relative frequencies, or probabilities, are 0.2, 0.4, 0.25, 0.1, and 0.05 respectively. Compute the mean and standard deviation of this distribution.