Finding the Fourth Proportional to 42,085.20, 63,137.68 and 12,503.28

Step by Step Solution

1. Step 1: Write the proportion equation
   42,085.20 : 63,137.68 = 12,503.28 : x
2. Step 2: Convert to fraction form
   42,085.20/63,137.68 = 12,503.28/x
3. Step 3: Cross multiply
   42,085.20x = 63,137.68 × 12,503.28
4. Step 4: Simplify right side
   42,085.20x = 789,428,091.59
5. Step 5: Solve for x
   x = 789,428,091.59/42,085.20
6. Step 6: Final answer
   x = 18,757.86