The number of ships to arrive at a harbor on any given day is a random variable represented by x. The probability distribution of x is as follows. (Give your answers correct to two decimal places.) x 10 11 12 13 14 P(x) 0.34 0.05 0.05 0.1 0.46 (a) Find the mean of the number of ships that arrive at a harbor on a given day. (b) Find the standard deviation, σ, of the number of ships that arrive at a harbor on a given day.