Finding the Fourth Proportional to 13,124.23, 18,128.72 and 9,728.12

Step by Step Solution

1. Step 1: Write the proportion equation
   13,124.23 : 18,128.72 = 9,728.12 : x
2. Step 2: Convert to fraction form
   13,124.23/18,128.72 = 9,728.12/x
3. Step 3: Cross multiply
   13,124.23x = 18,128.72 × 9,728.12
4. Step 4: Simplify right side
   13,124.23x = 176,358,363.61
5. Step 5: Solve for x
   x = 176,358,363.61/13,124.23
6. Step 6: Final answer
   x = 13,437.62