Finding the Fourth Proportional to 12,417.60, 17,131.20 and 7,940.16

Step by Step Solution

1. Step 1: Write the proportion equation
   12,417.60 : 17,131.20 = 7,940.16 : x
2. Step 2: Convert to fraction form
   12,417.60/17,131.20 = 7,940.16/x
3. Step 3: Cross multiply
   12,417.60x = 17,131.20 × 7,940.16
4. Step 4: Simplify right side
   12,417.60x = 136,024,468.99
5. Step 5: Solve for x
   x = 136,024,468.99/12,417.60
6. Step 6: Final answer
   x = 10,954.17