Finding the Fourth Proportional to 2,143.02, 3,215.43 and 911.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.02 : 3,215.43 = 911.31 : x
2. Step 2: Convert to fraction form
   2,143.02/3,215.43 = 911.31/x
3. Step 3: Cross multiply
   2,143.02x = 3,215.43 × 911.31
4. Step 4: Simplify right side
   2,143.02x = 2,930,253.51
5. Step 5: Solve for x
   x = 2,930,253.51/2,143.02
6. Step 6: Final answer
   x = 1,367.35