Finding the Fourth Proportional to 139,981.40, 210,059.18 and 56,875.40

Step by Step Solution

1. Step 1: Write the proportion equation
   139,981.40 : 210,059.18 = 56,875.40 : x
2. Step 2: Convert to fraction form
   139,981.40/210,059.18 = 56,875.40/x
3. Step 3: Cross multiply
   139,981.40x = 210,059.18 × 56,875.40
4. Step 4: Simplify right side
   139,981.40x = 11,947,198,551.50
5. Step 5: Solve for x
   x = 11,947,198,551.50/139,981.40
6. Step 6: Final answer
   x = 85,348.47