Finding the Fourth Proportional to 350,456.32, 525,712.56 and 139,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   350,456.32 : 525,712.56 = 139,978.72 : x
2. Step 2: Convert to fraction form
   350,456.32/525,712.56 = 139,978.72/x
3. Step 3: Cross multiply
   350,456.32x = 525,712.56 × 139,978.72
4. Step 4: Simplify right side
   350,456.32x = 73,588,571,236.72
5. Step 5: Solve for x
   x = 73,588,571,236.72/350,456.32
6. Step 6: Final answer
   x = 209,979.30