Finding the Fourth Proportional to 450,042.72, 620,766.30 and 288,642.12

Step by Step Solution

1. Step 1: Write the proportion equation
   450,042.72 : 620,766.30 = 288,642.12 : x
2. Step 2: Convert to fraction form
   450,042.72/620,766.30 = 288,642.12/x
3. Step 3: Cross multiply
   450,042.72x = 620,766.30 × 288,642.12
4. Step 4: Simplify right side
   450,042.72x = 179,179,300,856.56
5. Step 5: Solve for x
   x = 179,179,300,856.56/450,042.72
6. Step 6: Final answer
   x = 398,138.43