Answers

2015-03-10T20:11:45+05:30
Mean of 4 fish = 220
weight of 4 fish = 220 *4
weight of 4 fish = 880
880 - 310 / 3 = average weight of 4 fish
average weight of the 3 fish = 570 / 3
average weight of 4 fish = 190
BEST OF LUCK!!!
0
2015-03-10T20:34:14+05:30
Average weight before jumping = 220 = a +b + c + d/4 = a/4 + b/4 + c/4 +d/4
           a/4 + b/4 + c/4 + 310/4 = 220
           a/4 + b/4 + c/4 + 77.5 = 220
           a/4 +b/4 +c/4 =220 - 77.5 = 142.5
       By multiply both sides of equation by 4/3 we get
          a + b + c/3 = 142.5*4/3
          a + b + c/3 = 190
      average of weight after jumping = 190
0