Problem 3 (25 points) Annual maximum flows in the Pond Creek catchment area in the eastern United States are listed below in cubic meters per second for two periods of 12 years from 1945 to 1968. It is thought that changes in the flow regime during the middle of this period have modified the distribution of flows resulting in higher maximum flows. This is equivalent to stating that the mean flow has increased from the first period to the second period. State whether this statement is true or false based on the result of statistical testing at the level of significance a = 0.01. Assume normal populations. First period: 2000 1740 1460 2060 1530 1590 1690 1420 1330 607 1380 1660 Second period: 2290 2590 3260 2490 3080 2520 3360 8020 43 10 4380 3220 4320 You may use the following: x1 = 1539, X2 = 3653, $1 = 372, $2 = 1563, n1 = n2 = 12 (a) Assume population variances are equal to the sample variances. (b) Assume population variances are unknown and unequal