Variance before:
(1200 - 2.79)^2 * 0.00005 = 71.665589205
(240 - 2.79)^2 * 0.0001 = 5.62685841
(120 - 2.79)^2 * 0.00015 = 2.060727615
(25 - 2.79)^2 * 0.0008 = 0.39462728
(10 - 2.79)^2 * 0.01 = 0.519841
(6 - 2.79)^2 * 0.08 = 0.824328
(4 - 2.79)^2 * 0.13510 = 0.19779991
(2 - 2.79)^2 * 0.77380 = 0.48292858

71.665589205 + 5.62685841 + 2.060727615 + 0.39462728 + 0.519841 + 0.824328 + 0.19779991 + 0.48292858

= 81.7727
Standard deviation: 9.04282588575


Variance after:
(3600 - 2.79)^2 * 0.00001 = 129.399197841
(240 - 2.79)^2 * 0.00005 = 2.813429205
(120 - 2.79)^2 * 0.0001 = 1.37381841
(25 - 2.79)^2 * 0.001 = 0.4932841
(10 - 2.79)^2 * 0.005 = 0.2599205
(6 - 2.79)^2 * 0.075 = 0.7728075
(4 - 2.79)^2 * 0.18366 = 0.268896606
(2 - 2.79)^2 * 0.73518 = 0.458825838

129.399197841 + 2.813429205 + 1.37381841 + 0.4932841 + 0.2599205  + 0.7728075  + 0.268896606 + 0.458825838

= 135.84018
Standard deviation: 11.6550495494