Finding the Third Proportional to 682.31 and 909.56

Step by Step Solution

1. Step 1: Write the proportion equation
   682.31 : 909.56 = 909.56 : x
2. Step 2: Convert to fraction form
   682.31/909.56 = 909.56/x
3. Step 3: Cross multiply
   682.31x = 909.56 × 909.56
4. Step 4: Simplify right side
   682.31x = 827,303.94
5. Step 5: Solve for x
   x = 827,303.94/682.31
6. Step 6: Final answer
   x = 1,212.50