Finding the Fourth Proportional to 13,385.99, 20,073.15 and 7,144.61

Step by Step Solution

1. Step 1: Write the proportion equation
   13,385.99 : 20,073.15 = 7,144.61 : x
2. Step 2: Convert to fraction form
   13,385.99/20,073.15 = 7,144.61/x
3. Step 3: Cross multiply
   13,385.99x = 20,073.15 × 7,144.61
4. Step 4: Simplify right side
   13,385.99x = 143,414,727.86
5. Step 5: Solve for x
   x = 143,414,727.86/13,385.99
6. Step 6: Final answer
   x = 10,713.80