Finding the Fourth Proportional to 56,840.50, 78,439.89 and 31,690

Step by Step Solution

1. Step 1: Write the proportion equation
   56,840.50 : 78,439.89 = 31,690 : x
2. Step 2: Convert to fraction form
   56,840.50/78,439.89 = 31,690/x
3. Step 3: Cross multiply
   56,840.50x = 78,439.89 × 31,690
4. Step 4: Simplify right side
   56,840.50x = 2,485,760,114.10
5. Step 5: Solve for x
   x = 2,485,760,114.10/56,840.50
6. Step 6: Final answer
   x = 43,732.20