Finding the Fourth Proportional to 139,428.16, 209,049.78 and 50,671.12

Step by Step Solution

1. Step 1: Write the proportion equation
   139,428.16 : 209,049.78 = 50,671.12 : x
2. Step 2: Convert to fraction form
   139,428.16/209,049.78 = 50,671.12/x
3. Step 3: Cross multiply
   139,428.16x = 209,049.78 × 50,671.12
4. Step 4: Simplify right side
   139,428.16x = 10,592,786,488.35
5. Step 5: Solve for x
   x = 10,592,786,488.35/139,428.16
6. Step 6: Final answer
   x = 75,973.08