The number of arrivals per minute at a bank located in the central business district of a large city was recorded over a a. Compute the mean number of arrivals per minute. period of 200 minutes with the results shown in the table below. Complete (a) and (b) to the right. Arrivals H= 2.55 Frequency 21 (Round to three decimal places as needed.) b. Compute the standard deviation. (Round to three decimal places as needed.)