Finding the Fourth Proportional to 2,665.71, 3,998.43 and 816.83

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.71 : 3,998.43 = 816.83 : x
2. Step 2: Convert to fraction form
   2,665.71/3,998.43 = 816.83/x
3. Step 3: Cross multiply
   2,665.71x = 3,998.43 × 816.83
4. Step 4: Simplify right side
   2,665.71x = 3,266,053.90
5. Step 5: Solve for x
   x = 3,266,053.90/2,665.71
6. Step 6: Final answer
   x = 1,225.21