Problcm A drainage channel has a capacity sufficient to carry 800 cubic feet per second. following data regarding the probability that a given water flow in any one year will be exceeded, and the cost of enlarging the channel: Engineering studies produce the Probability of overflow Drainage capacity (Cubic feet per secend 800 1,200 1.300 1.900 Investment capital to enlarge the channel 0.30 0.20 0.10 0.05 $25.000 75,000 90,000 Records indicate that the annual average property damage amounts to $30,000 when serious overflow occurs It is believed that this would be the average damage whenever the storm flow is greater than the capacity of the channel. Reconstruction of the channel would be financed by 20-year bonds bearing 10% annual interest compounded (and paid) annually. Determine the most economical size of the channe