Finding the Fourth Proportional to 12,884.20, 17,784.42 and 7,578.76

Step by Step Solution

1. Step 1: Write the proportion equation
   12,884.20 : 17,784.42 = 7,578.76 : x
2. Step 2: Convert to fraction form
   12,884.20/17,784.42 = 7,578.76/x
3. Step 3: Cross multiply
   12,884.20x = 17,784.42 × 7,578.76
4. Step 4: Simplify right side
   12,884.20x = 134,783,850.92
5. Step 5: Solve for x
   x = 134,783,850.92/12,884.20
6. Step 6: Final answer
   x = 10,461.17