Finding the Fourth Proportional to 23,128.28, 31,917.16 and 13,057.12

Step by Step Solution

1. Step 1: Write the proportion equation
   23,128.28 : 31,917.16 = 13,057.12 : x
2. Step 2: Convert to fraction form
   23,128.28/31,917.16 = 13,057.12/x
3. Step 3: Cross multiply
   23,128.28x = 31,917.16 × 13,057.12
4. Step 4: Simplify right side
   23,128.28x = 416,746,188.18
5. Step 5: Solve for x
   x = 416,746,188.18/23,128.28
6. Step 6: Final answer
   x = 18,018.90