Finding the Fourth Proportional to 1,304.80, 1,800.72 and 781.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,304.80 : 1,800.72 = 781.12 : x
2. Step 2: Convert to fraction form
   1,304.80/1,800.72 = 781.12/x
3. Step 3: Cross multiply
   1,304.80x = 1,800.72 × 781.12
4. Step 4: Simplify right side
   1,304.80x = 1,406,578.41
5. Step 5: Solve for x
   x = 1,406,578.41/1,304.80
6. Step 6: Final answer
   x = 1,078.00