Finding the Fourth Proportional to 1,281.72, 1,768.24 and 783.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,281.72 : 1,768.24 = 783.96 : x
2. Step 2: Convert to fraction form
   1,281.72/1,768.24 = 783.96/x
3. Step 3: Cross multiply
   1,281.72x = 1,768.24 × 783.96
4. Step 4: Simplify right side
   1,281.72x = 1,386,229.43
5. Step 5: Solve for x
   x = 1,386,229.43/1,281.72
6. Step 6: Final answer
   x = 1,081.54