Finding the Fourth Proportional to 12,691.13, 17,513.78 and 7,389.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,691.13 : 17,513.78 = 7,389.50 : x
2. Step 2: Convert to fraction form
   12,691.13/17,513.78 = 7,389.50/x
3. Step 3: Cross multiply
   12,691.13x = 17,513.78 × 7,389.50
4. Step 4: Simplify right side
   12,691.13x = 129,417,952.79
5. Step 5: Solve for x
   x = 129,417,952.79/12,691.13
6. Step 6: Final answer
   x = 10,197.52