Finding the Fourth Proportional to 1,247.52, 1,721.33 and 781.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,247.52 : 1,721.33 = 781.50 : x
2. Step 2: Convert to fraction form
   1,247.52/1,721.33 = 781.50/x
3. Step 3: Cross multiply
   1,247.52x = 1,721.33 × 781.50
4. Step 4: Simplify right side
   1,247.52x = 1,345,215.49
5. Step 5: Solve for x
   x = 1,345,215.49/1,247.52
6. Step 6: Final answer
   x = 1,078.31