Finding the Fourth Proportional to 139,142.88, 208,744.56 and 45,645.12

Step by Step Solution

1. Step 1: Write the proportion equation
   139,142.88 : 208,744.56 = 45,645.12 : x
2. Step 2: Convert to fraction form
   139,142.88/208,744.56 = 45,645.12/x
3. Step 3: Cross multiply
   139,142.88x = 208,744.56 × 45,645.12
4. Step 4: Simplify right side
   139,142.88x = 9,528,170,490.55
5. Step 5: Solve for x
   x = 9,528,170,490.55/139,142.88
6. Step 6: Final answer
   x = 68,477.60