Finding the Fourth Proportional to 1,443.76, 1,992.38 and 780.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.76 : 1,992.38 = 780.61 : x
2. Step 2: Convert to fraction form
   1,443.76/1,992.38 = 780.61/x
3. Step 3: Cross multiply
   1,443.76x = 1,992.38 × 780.61
4. Step 4: Simplify right side
   1,443.76x = 1,555,264.28
5. Step 5: Solve for x
   x = 1,555,264.28/1,443.76
6. Step 6: Final answer
   x = 1,077.23