Finding the Fourth Proportional to 12,405.91, 17,120.92 and 7,100.61

Step by Step Solution

1. Step 1: Write the proportion equation
   12,405.91 : 17,120.92 = 7,100.61 : x
2. Step 2: Convert to fraction form
   12,405.91/17,120.92 = 7,100.61/x
3. Step 3: Cross multiply
   12,405.91x = 17,120.92 × 7,100.61
4. Step 4: Simplify right side
   12,405.91x = 121,569,036.32
5. Step 5: Solve for x
   x = 121,569,036.32/12,405.91
6. Step 6: Final answer
   x = 9,799.28