Finding the Fourth Proportional to 492,100.34, 679,007.48 and 288,140.72

Step by Step Solution

1. Step 1: Write the proportion equation
   492,100.34 : 679,007.48 = 288,140.72 : x
2. Step 2: Convert to fraction form
   492,100.34/679,007.48 = 288,140.72/x
3. Step 3: Cross multiply
   492,100.34x = 679,007.48 × 288,140.72
4. Step 4: Simplify right side
   492,100.34x = 195,649,704,172.59
5. Step 5: Solve for x
   x = 195,649,704,172.59/492,100.34
6. Step 6: Final answer
   x = 397,580.92