Finding the Fourth Proportional to 139,729.50, 209,678.34 and 50,990.76

Step by Step Solution

1. Step 1: Write the proportion equation
   139,729.50 : 209,678.34 = 50,990.76 : x
2. Step 2: Convert to fraction form
   139,729.50/209,678.34 = 50,990.76/x
3. Step 3: Cross multiply
   139,729.50x = 209,678.34 × 50,990.76
4. Step 4: Simplify right side
   139,729.50x = 10,691,657,912.14
5. Step 5: Solve for x
   x = 10,691,657,912.14/139,729.50
6. Step 6: Final answer
   x = 76,516.83