Average water levels of 29-year floods were measured in the Sakarya River. Observed water levels in cm are given below: 543, 705, 829, 710, 518, 609, 652, 558, 478, 753, 679, 583, 497, 597, 801, 697, 460, 631, 908, 734, 762, 641, 725, 430, 575, 531, 785, 1027, 446 a) Using the observed values above, explain why they fit the lognormal probability distribution.. b) Find future values for 50, 100, 250, 500 and 1000 year periods using the frequency factor method.