A 911 service center recorded the number of calls received per

     A 911 service center   recorded the number of calls received per hour. The random variable x   represents the number of calls per hour for one week.         x 0 1 2 3 4 5 6 7   P(x) 0.01 0.10 0.26 0.33 0.18 0.06 0.03   0.03      Find the mean, variance, standard   deviation, expected value of the probability of distribution and interpret   the results