Finding the Fourth Proportional to 139,803.84, 209,712.69 and 39,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   139,803.84 : 209,712.69 = 39,978.72 : x
2. Step 2: Convert to fraction form
   139,803.84/209,712.69 = 39,978.72/x
3. Step 3: Cross multiply
   139,803.84x = 209,712.69 × 39,978.72
4. Step 4: Simplify right side
   139,803.84x = 8,384,044,913.96
5. Step 5: Solve for x
   x = 8,384,044,913.96/139,803.84
6. Step 6: Final answer
   x = 59,970.06