Finding the Fourth Proportional to 820.42, 1,132.25 and 488.72

Step by Step Solution

1. Step 1: Write the proportion equation
   820.42 : 1,132.25 = 488.72 : x
2. Step 2: Convert to fraction form
   820.42/1,132.25 = 488.72/x
3. Step 3: Cross multiply
   820.42x = 1,132.25 × 488.72
4. Step 4: Simplify right side
   820.42x = 553,353.61
5. Step 5: Solve for x
   x = 553,353.61/820.42
6. Step 6: Final answer
   x = 674.48