Finding the Fourth Proportional to 1,280.61, 1,759.58 and 1,018.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,280.61 : 1,759.58 = 1,018.17 : x
2. Step 2: Convert to fraction form
   1,280.61/1,759.58 = 1,018.17/x
3. Step 3: Cross multiply
   1,280.61x = 1,759.58 × 1,018.17
4. Step 4: Simplify right side
   1,280.61x = 1,791,551.57
5. Step 5: Solve for x
   x = 1,791,551.57/1,280.61
6. Step 6: Final answer
   x = 1,398.98