Finding the Fourth Proportional to 1,281.43, 1,768.42 and 721.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,281.43 : 1,768.42 = 721.89 : x
2. Step 2: Convert to fraction form
   1,281.43/1,768.42 = 721.89/x
3. Step 3: Cross multiply
   1,281.43x = 1,768.42 × 721.89
4. Step 4: Simplify right side
   1,281.43x = 1,276,604.71
5. Step 5: Solve for x
   x = 1,276,604.71/1,281.43
6. Step 6: Final answer
   x = 996.23