Finding the Fourth Proportional to 2,660.91, 3,991.83 and 905.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,660.91 : 3,991.83 = 905.82 : x
2. Step 2: Convert to fraction form
   2,660.91/3,991.83 = 905.82/x
3. Step 3: Cross multiply
   2,660.91x = 3,991.83 × 905.82
4. Step 4: Simplify right side
   2,660.91x = 3,615,879.45
5. Step 5: Solve for x
   x = 3,615,879.45/2,660.91
6. Step 6: Final answer
   x = 1,358.89