Finding the Fourth Proportional to 101,215.50, 139,677.40 and 56,503.50

Step by Step Solution

1. Step 1: Write the proportion equation
   101,215.50 : 139,677.40 = 56,503.50 : x
2. Step 2: Convert to fraction form
   101,215.50/139,677.40 = 56,503.50/x
3. Step 3: Cross multiply
   101,215.50x = 139,677.40 × 56,503.50
4. Step 4: Simplify right side
   101,215.50x = 7,892,261,970.90
5. Step 5: Solve for x
   x = 7,892,261,970.90/101,215.50
6. Step 6: Final answer
   x = 77,974.84