Finding the Fourth Proportional to 402,478.47, 555,433.61 and 221,196.83

Step by Step Solution

1. Step 1: Write the proportion equation
   402,478.47 : 555,433.61 = 221,196.83 : x
2. Step 2: Convert to fraction form
   402,478.47/555,433.61 = 221,196.83/x
3. Step 3: Cross multiply
   402,478.47x = 555,433.61 × 221,196.83
4. Step 4: Simplify right side
   402,478.47x = 122,860,149,924.30
5. Step 5: Solve for x
   x = 122,860,149,924.30/402,478.47
6. Step 6: Final answer
   x = 305,258.94