Finding the Third Proportional to 2,615.20 and 5,631.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,615.20 : 5,631.61 = 5,631.61 : x
2. Step 2: Convert to fraction form
   2,615.20/5,631.61 = 5,631.61/x
3. Step 3: Cross multiply
   2,615.20x = 5,631.61 × 5,631.61
4. Step 4: Simplify right side
   2,615.20x = 31,715,024.15
5. Step 5: Solve for x
   x = 31,715,024.15/2,615.20
6. Step 6: Final answer
   x = 12,127.17