Finding the Fourth Proportional to 31,688.42, 43,725.42 and 20,358.88

Step by Step Solution

1. Step 1: Write the proportion equation
   31,688.42 : 43,725.42 = 20,358.88 : x
2. Step 2: Convert to fraction form
   31,688.42/43,725.42 = 20,358.88/x
3. Step 3: Cross multiply
   31,688.42x = 43,725.42 × 20,358.88
4. Step 4: Simplify right side
   31,688.42x = 890,200,469.42
5. Step 5: Solve for x
   x = 890,200,469.42/31,688.42
6. Step 6: Final answer
   x = 28,092.30