Finding the Fourth Proportional to 1,280.73, 1,767.50 and 721.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,280.73 : 1,767.50 = 721.25 : x
2. Step 2: Convert to fraction form
   1,280.73/1,767.50 = 721.25/x
3. Step 3: Cross multiply
   1,280.73x = 1,767.50 × 721.25
4. Step 4: Simplify right side
   1,280.73x = 1,274,805.77
5. Step 5: Solve for x
   x = 1,274,805.77/1,280.73
6. Step 6: Final answer
   x = 995.37