Finding the Fourth Proportional to 2,143.83, 3,216.33 and 911.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.83 : 3,216.33 = 911.31 : x
2. Step 2: Convert to fraction form
   2,143.83/3,216.33 = 911.31/x
3. Step 3: Cross multiply
   2,143.83x = 3,216.33 × 911.31
4. Step 4: Simplify right side
   2,143.83x = 2,931,073.69
5. Step 5: Solve for x
   x = 2,931,073.69/2,143.83
6. Step 6: Final answer
   x = 1,367.21