Finding the Third Proportional to 280.69 and 505.69

Step by Step Solution

1. Step 1: Write the proportion equation
   280.69 : 505.69 = 505.69 : x
2. Step 2: Convert to fraction form
   280.69/505.69 = 505.69/x
3. Step 3: Cross multiply
   280.69x = 505.69 × 505.69
4. Step 4: Simplify right side
   280.69x = 255,719.85
5. Step 5: Solve for x
   x = 255,719.85/280.69
6. Step 6: Final answer
   x = 911.05