Finding the Fourth Proportional to 1,597.54, 2,391.86 and 815.85

Step by Step Solution

1. Step 1: Write the proportion equation
   1,597.54 : 2,391.86 = 815.85 : x
2. Step 2: Convert to fraction form
   1,597.54/2,391.86 = 815.85/x
3. Step 3: Cross multiply
   1,597.54x = 2,391.86 × 815.85
4. Step 4: Simplify right side
   1,597.54x = 1,951,401.02
5. Step 5: Solve for x
   x = 1,951,401.02/1,597.54
6. Step 6: Final answer
   x = 1,221.51