Finding the Fourth Proportional to 12,884.86, 17,780.02 and 7,142.47

Step by Step Solution

1. Step 1: Write the proportion equation
   12,884.86 : 17,780.02 = 7,142.47 : x
2. Step 2: Convert to fraction form
   12,884.86/17,780.02 = 7,142.47/x
3. Step 3: Cross multiply
   12,884.86x = 17,780.02 × 7,142.47
4. Step 4: Simplify right side
   12,884.86x = 126,993,259.45
5. Step 5: Solve for x
   x = 126,993,259.45/12,884.86
6. Step 6: Final answer
   x = 9,856.01