The average rainfall is important for designing reservoirs. Statistical data shows the average yearly rainfall in Norfolk follows a normal distribution with a mean of 47 in. and a standard deviation of 9 in. (Data retrieved from https://forecast.weather.gov/) a. What is the probability we will have between 39 and 49 in. of rain this year? b. Assume we had 18 in. of rainfall this year, what is the probability we will have at least another 30 in. by the end of the year? c. What amount should be used to design for the 85th percentile rainfall