Finding the Fourth Proportional to 139,968.30, 210,171.15 and 80,919.30

Step by Step Solution

1. Step 1: Write the proportion equation
   139,968.30 : 210,171.15 = 80,919.30 : x
2. Step 2: Convert to fraction form
   139,968.30/210,171.15 = 80,919.30/x
3. Step 3: Cross multiply
   139,968.30x = 210,171.15 × 80,919.30
4. Step 4: Simplify right side
   139,968.30x = 17,006,902,338.20
5. Step 5: Solve for x
   x = 17,006,902,338.20/139,968.30
6. Step 6: Final answer
   x = 121,505.39