Finding the Fourth Proportional to 31,085.40, 42,903.40 and 18,337.80

Step by Step Solution

1. Step 1: Write the proportion equation
   31,085.40 : 42,903.40 = 18,337.80 : x
2. Step 2: Convert to fraction form
   31,085.40/42,903.40 = 18,337.80/x
3. Step 3: Cross multiply
   31,085.40x = 42,903.40 × 18,337.80
4. Step 4: Simplify right side
   31,085.40x = 786,753,968.52
5. Step 5: Solve for x
   x = 786,753,968.52/31,085.40
6. Step 6: Final answer
   x = 25,309.44