Finding the Fourth Proportional to 2,665.17, 3,997.49 and 816.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.17 : 3,997.49 = 816.30 : x
2. Step 2: Convert to fraction form
   2,665.17/3,997.49 = 816.30/x
3. Step 3: Cross multiply
   2,665.17x = 3,997.49 × 816.30
4. Step 4: Simplify right side
   2,665.17x = 3,263,147.01
5. Step 5: Solve for x
   x = 3,263,147.01/2,665.17
6. Step 6: Final answer
   x = 1,224.37