Finding the Fourth Proportional to 56,639.25, 78,162.17 and 31,146.05

Step by Step Solution

1. Step 1: Write the proportion equation
   56,639.25 : 78,162.17 = 31,146.05 : x
2. Step 2: Convert to fraction form
   56,639.25/78,162.17 = 31,146.05/x
3. Step 3: Cross multiply
   56,639.25x = 78,162.17 × 31,146.05
4. Step 4: Simplify right side
   56,639.25x = 2,434,442,894.60
5. Step 5: Solve for x
   x = 2,434,442,894.60/56,639.25
6. Step 6: Final answer
   x = 42,981.55