Finding the Fourth Proportional to 12,689.55, 17,509.37 and 7,310.79

Step by Step Solution

1. Step 1: Write the proportion equation
   12,689.55 : 17,509.37 = 7,310.79 : x
2. Step 2: Convert to fraction form
   12,689.55/17,509.37 = 7,310.79/x
3. Step 3: Cross multiply
   12,689.55x = 17,509.37 × 7,310.79
4. Step 4: Simplify right side
   12,689.55x = 128,007,290.55
5. Step 5: Solve for x
   x = 128,007,290.55/12,689.55
6. Step 6: Final answer
   x = 10,087.61