Finding the Fourth Proportional to 1,280.23, 1,766.69 and 720.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,280.23 : 1,766.69 = 720.69 : x
2. Step 2: Convert to fraction form
   1,280.23/1,766.69 = 720.69/x
3. Step 3: Cross multiply
   1,280.23x = 1,766.69 × 720.69
4. Step 4: Simplify right side
   1,280.23x = 1,273,247.25
5. Step 5: Solve for x
   x = 1,273,247.25/1,280.23
6. Step 6: Final answer
   x = 994.55