Finding the Fourth Proportional to 20,499.12, 30,717.36 and 12,162.72

Step by Step Solution

1. Step 1: Write the proportion equation
   20,499.12 : 30,717.36 = 12,162.72 : x
2. Step 2: Convert to fraction form
   20,499.12/30,717.36 = 12,162.72/x
3. Step 3: Cross multiply
   20,499.12x = 30,717.36 × 12,162.72
4. Step 4: Simplify right side
   20,499.12x = 373,606,648.82
5. Step 5: Solve for x
   x = 373,606,648.82/20,499.12
6. Step 6: Final answer
   x = 18,225.50