Finding the Fourth Proportional to 3,404.11, 5,105.55 and 905.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,404.11 : 5,105.55 = 905.31 : x
2. Step 2: Convert to fraction form
   3,404.11/5,105.55 = 905.31/x
3. Step 3: Cross multiply
   3,404.11x = 5,105.55 × 905.31
4. Step 4: Simplify right side
   3,404.11x = 4,622,099.29
5. Step 5: Solve for x
   x = 4,622,099.29/3,404.11
6. Step 6: Final answer
   x = 1,357.80