Finding the Fourth Proportional to 20,085.12, 30,145.98 and 10,231.20

Step by Step Solution

1. Step 1: Write the proportion equation
   20,085.12 : 30,145.98 = 10,231.20 : x
2. Step 2: Convert to fraction form
   20,085.12/30,145.98 = 10,231.20/x
3. Step 3: Cross multiply
   20,085.12x = 30,145.98 × 10,231.20
4. Step 4: Simplify right side
   20,085.12x = 308,429,550.58
5. Step 5: Solve for x
   x = 308,429,550.58/20,085.12
6. Step 6: Final answer
   x = 15,356.12