Finding the Fourth Proportional to 1,280.74, 1,763.97 and 1,105.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,280.74 : 1,763.97 = 1,105.78 : x
2. Step 2: Convert to fraction form
   1,280.74/1,763.97 = 1,105.78/x
3. Step 3: Cross multiply
   1,280.74x = 1,763.97 × 1,105.78
4. Step 4: Simplify right side
   1,280.74x = 1,950,562.75
5. Step 5: Solve for x
   x = 1,950,562.75/1,280.74
6. Step 6: Final answer
   x = 1,523.00