Finding the Fourth Proportional to 1,279.72, 1,765.96 and 782.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.72 : 1,765.96 = 782.24 : x
2. Step 2: Convert to fraction form
   1,279.72/1,765.96 = 782.24/x
3. Step 3: Cross multiply
   1,279.72x = 1,765.96 × 782.24
4. Step 4: Simplify right side
   1,279.72x = 1,381,404.55
5. Step 5: Solve for x
   x = 1,381,404.55/1,279.72
6. Step 6: Final answer
   x = 1,079.46