The Runoff in the Westfield River near Springfield MA for 15 months is as follows:
| Year |
Flow (Million Gallons Per Month) |
| 1 |
100 |
| 2 |
100 |
| 3 |
50 |
| 4 |
5 |
| 5 |
8 |
| 6 |
2 |
| 7 |
2 |
| 8 |
10 |
| 9 |
6 |
| 10 |
20 |
| 11 |
50 |
| 12 |
120 |
| 13 |
40 |
| 14 |
25 |
| 15 |
30 |
The objective is to draw a constant draft of 23 million gallons per month from this river. How large would the impoundment have to be to provide such a water supply for Springfield during this drought? Please present data in Graphical form