Finding the Fourth Proportional to 85,799.72, 128,612.10 and 52,499

Step by Step Solution

1. Step 1: Write the proportion equation
   85,799.72 : 128,612.10 = 52,499 : x
2. Step 2: Convert to fraction form
   85,799.72/128,612.10 = 52,499/x
3. Step 3: Cross multiply
   85,799.72x = 128,612.10 × 52,499
4. Step 4: Simplify right side
   85,799.72x = 6,752,006,637.90
5. Step 5: Solve for x
   x = 6,752,006,637.90/85,799.72
6. Step 6: Final answer
   x = 78,694.97