Finding the Third Proportional to 259.31 and 505.69

Step by Step Solution

1. Step 1: Write the proportion equation
   259.31 : 505.69 = 505.69 : x
2. Step 2: Convert to fraction form
   259.31/505.69 = 505.69/x
3. Step 3: Cross multiply
   259.31x = 505.69 × 505.69
4. Step 4: Simplify right side
   259.31x = 255,719.85
5. Step 5: Solve for x
   x = 255,719.85/259.31
6. Step 6: Final answer
   x = 986.15