Finding the Fourth Proportional to 72,308.08, 99,715.05 and 56,386.72

Step by Step Solution

1. Step 1: Write the proportion equation
   72,308.08 : 99,715.05 = 56,386.72 : x
2. Step 2: Convert to fraction form
   72,308.08/99,715.05 = 56,386.72/x
3. Step 3: Cross multiply
   72,308.08x = 99,715.05 × 56,386.72
4. Step 4: Simplify right side
   72,308.08x = 5,622,604,604.14
5. Step 5: Solve for x
   x = 5,622,604,604.14/72,308.08
6. Step 6: Final answer
   x = 77,759.01