Finding the Fourth Proportional to 389,978.58, 584,968.05 and 140,660.58

Step by Step Solution

1. Step 1: Write the proportion equation
   389,978.58 : 584,968.05 = 140,660.58 : x
2. Step 2: Convert to fraction form
   389,978.58/584,968.05 = 140,660.58/x
3. Step 3: Cross multiply
   389,978.58x = 584,968.05 × 140,660.58
4. Step 4: Simplify right side
   389,978.58x = 82,281,945,194.47
5. Step 5: Solve for x
   x = 82,281,945,194.47/389,978.58
6. Step 6: Final answer
   x = 210,990.93