Finding the Fourth Proportional to 207,640.30, 311,499.25 and 142,997.31

Step by Step Solution

1. Step 1: Write the proportion equation
   207,640.30 : 311,499.25 = 142,997.31 : x
2. Step 2: Convert to fraction form
   207,640.30/311,499.25 = 142,997.31/x
3. Step 3: Cross multiply
   207,640.30x = 311,499.25 × 142,997.31
4. Step 4: Simplify right side
   207,640.30x = 44,543,555,043.59
5. Step 5: Solve for x
   x = 44,543,555,043.59/207,640.30
6. Step 6: Final answer
   x = 214,522.69