Finding the Fourth Proportional to 820.73, 1,224.18 and 697.61

Step by Step Solution

1. Step 1: Write the proportion equation
   820.73 : 1,224.18 = 697.61 : x
2. Step 2: Convert to fraction form
   820.73/1,224.18 = 697.61/x
3. Step 3: Cross multiply
   820.73x = 1,224.18 × 697.61
4. Step 4: Simplify right side
   820.73x = 854,003.27
5. Step 5: Solve for x
   x = 854,003.27/820.73
6. Step 6: Final answer
   x = 1,040.54