Finding the Fourth Proportional to 2,665.41, 3,997.10 and 815.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.41 : 3,997.10 = 815.96 : x
2. Step 2: Convert to fraction form
   2,665.41/3,997.10 = 815.96/x
3. Step 3: Cross multiply
   2,665.41x = 3,997.10 × 815.96
4. Step 4: Simplify right side
   2,665.41x = 3,261,449.65
5. Step 5: Solve for x
   x = 3,261,449.65/2,665.41
6. Step 6: Final answer
   x = 1,223.62