Finding the Fourth Proportional to 2,143.98, 3,216.38 and 911.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.98 : 3,216.38 = 911.39 : x
2. Step 2: Convert to fraction form
   2,143.98/3,216.38 = 911.39/x
3. Step 3: Cross multiply
   2,143.98x = 3,216.38 × 911.39
4. Step 4: Simplify right side
   2,143.98x = 2,931,355.93
5. Step 5: Solve for x
   x = 2,931,355.93/2,143.98
6. Step 6: Final answer
   x = 1,367.25