Finding the Third Proportional to 314.50 and 685.25

Step by Step Solution

1. Step 1: Write the proportion equation
   314.50 : 685.25 = 685.25 : x
2. Step 2: Convert to fraction form
   314.50/685.25 = 685.25/x
3. Step 3: Cross multiply
   314.50x = 685.25 × 685.25
4. Step 4: Simplify right side
   314.50x = 469,567.56
5. Step 5: Solve for x
   x = 469,567.56/314.50
6. Step 6: Final answer
   x = 1,493.06