Finding the Third Proportional to 687.25 and 909.38

Step by Step Solution

1. Step 1: Write the proportion equation
   687.25 : 909.38 = 909.38 : x
2. Step 2: Convert to fraction form
   687.25/909.38 = 909.38/x
3. Step 3: Cross multiply
   687.25x = 909.38 × 909.38
4. Step 4: Simplify right side
   687.25x = 826,962.89
5. Step 5: Solve for x
   x = 826,962.89/687.25
6. Step 6: Final answer
   x = 1,203.29