Finding the Third Proportional to 685.55 and 783.42

Step by Step Solution

1. Step 1: Write the proportion equation
   685.55 : 783.42 = 783.42 : x
2. Step 2: Convert to fraction form
   685.55/783.42 = 783.42/x
3. Step 3: Cross multiply
   685.55x = 783.42 × 783.42
4. Step 4: Simplify right side
   685.55x = 613,749.83
5. Step 5: Solve for x
   x = 613,749.83/685.55
6. Step 6: Final answer
   x = 895.27