Finding the Fourth Proportional to 2,665.31, 3,997.76 and 816.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.31 : 3,997.76 = 816.42 : x
2. Step 2: Convert to fraction form
   2,665.31/3,997.76 = 816.42/x
3. Step 3: Cross multiply
   2,665.31x = 3,997.76 × 816.42
4. Step 4: Simplify right side
   2,665.31x = 3,263,847.14
5. Step 5: Solve for x
   x = 3,263,847.14/2,665.31
6. Step 6: Final answer
   x = 1,224.57