Finding the Fourth Proportional to 85,310.42, 128,042.78 and 43,219.58

Step by Step Solution

1. Step 1: Write the proportion equation
   85,310.42 : 128,042.78 = 43,219.58 : x
2. Step 2: Convert to fraction form
   85,310.42/128,042.78 = 43,219.58/x
3. Step 3: Cross multiply
   85,310.42x = 128,042.78 × 43,219.58
4. Step 4: Simplify right side
   85,310.42x = 5,533,954,317.32
5. Step 5: Solve for x
   x = 5,533,954,317.32/85,310.42
6. Step 6: Final answer
   x = 64,868.45