Finding the Fourth Proportional to 492,616.79, 679,818.71 and 288,618.89

Step by Step Solution

1. Step 1: Write the proportion equation
   492,616.79 : 679,818.71 = 288,618.89 : x
2. Step 2: Convert to fraction form
   492,616.79/679,818.71 = 288,618.89/x
3. Step 3: Cross multiply
   492,616.79x = 679,818.71 × 288,618.89
4. Step 4: Simplify right side
   492,616.79x = 196,208,520,038.34
5. Step 5: Solve for x
   x = 196,208,520,038.34/492,616.79
6. Step 6: Final answer
   x = 398,298.49