Finding the Third Proportional to 445.50 and 685.88

Step by Step Solution

1. Step 1: Write the proportion equation
   445.50 : 685.88 = 685.88 : x
2. Step 2: Convert to fraction form
   445.50/685.88 = 685.88/x
3. Step 3: Cross multiply
   445.50x = 685.88 × 685.88
4. Step 4: Simplify right side
   445.50x = 470,424.52
5. Step 5: Solve for x
   x = 470,424.52/445.50
6. Step 6: Final answer
   x = 1,055.95