Finding the Fourth Proportional to 1,279.86, 1,766.27 and 720.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.86 : 1,766.27 = 720.42 : x
2. Step 2: Convert to fraction form
   1,279.86/1,766.27 = 720.42/x
3. Step 3: Cross multiply
   1,279.86x = 1,766.27 × 720.42
4. Step 4: Simplify right side
   1,279.86x = 1,272,443.80
5. Step 5: Solve for x
   x = 1,272,443.80/1,279.86
6. Step 6: Final answer
   x = 994.21