Finding the Fourth Proportional to 221,086.55, 331,699.91 and 78,928.72

Step by Step Solution

1. Step 1: Write the proportion equation
   221,086.55 : 331,699.91 = 78,928.72 : x
2. Step 2: Convert to fraction form
   221,086.55/331,699.91 = 78,928.72/x
3. Step 3: Cross multiply
   221,086.55x = 331,699.91 × 78,928.72
4. Step 4: Simplify right side
   221,086.55x = 26,180,649,320.42
5. Step 5: Solve for x
   x = 26,180,649,320.42/221,086.55
6. Step 6: Final answer
   x = 118,418.10