Finding the Fourth Proportional to 2,144.30, 3,216.60 and 911.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,144.30 : 3,216.60 = 911.57 : x
2. Step 2: Convert to fraction form
   2,144.30/3,216.60 = 911.57/x
3. Step 3: Cross multiply
   2,144.30x = 3,216.60 × 911.57
4. Step 4: Simplify right side
   2,144.30x = 2,932,156.06
5. Step 5: Solve for x
   x = 2,932,156.06/2,144.30
6. Step 6: Final answer
   x = 1,367.42