Finding the Third Proportional to 472.13 and 685.31

Step by Step Solution

1. Step 1: Write the proportion equation
   472.13 : 685.31 = 685.31 : x
2. Step 2: Convert to fraction form
   472.13/685.31 = 685.31/x
3. Step 3: Cross multiply
   472.13x = 685.31 × 685.31
4. Step 4: Simplify right side
   472.13x = 469,653.22
5. Step 5: Solve for x
   x = 469,653.22/472.13
6. Step 6: Final answer
   x = 994.76