Finding the Fourth Proportional to 72,131.20, 99,568.83 and 64,564.18

Step by Step Solution

1. Step 1: Write the proportion equation
   72,131.20 : 99,568.83 = 64,564.18 : x
2. Step 2: Convert to fraction form
   72,131.20/99,568.83 = 64,564.18/x
3. Step 3: Cross multiply
   72,131.20x = 99,568.83 × 64,564.18
4. Step 4: Simplify right side
   72,131.20x = 6,428,579,862.51
5. Step 5: Solve for x
   x = 6,428,579,862.51/72,131.20
6. Step 6: Final answer
   x = 89,123.43