Finding the Fourth Proportional to 1,279.98, 1,766.36 and 712.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.98 : 1,766.36 = 712.81 : x
2. Step 2: Convert to fraction form
   1,279.98/1,766.36 = 712.81/x
3. Step 3: Cross multiply
   1,279.98x = 1,766.36 × 712.81
4. Step 4: Simplify right side
   1,279.98x = 1,259,079.07
5. Step 5: Solve for x
   x = 1,259,079.07/1,279.98
6. Step 6: Final answer
   x = 983.67