Finding the Fourth Proportional to 31,103.70, 42,929.10 and 20,492.70

Step by Step Solution

1. Step 1: Write the proportion equation
   31,103.70 : 42,929.10 = 20,492.70 : x
2. Step 2: Convert to fraction form
   31,103.70/42,929.10 = 20,492.70/x
3. Step 3: Cross multiply
   31,103.70x = 42,929.10 × 20,492.70
4. Step 4: Simplify right side
   31,103.70x = 879,733,167.57
5. Step 5: Solve for x
   x = 879,733,167.57/31,103.70
6. Step 6: Final answer
   x = 28,283.88