Finding the Third Proportional to 166.25 and 255.25

Step by Step Solution

1. Step 1: Write the proportion equation
   166.25 : 255.25 = 255.25 : x
2. Step 2: Convert to fraction form
   166.25/255.25 = 255.25/x
3. Step 3: Cross multiply
   166.25x = 255.25 × 255.25
4. Step 4: Simplify right side
   166.25x = 65,152.56
5. Step 5: Solve for x
   x = 65,152.56/166.25
6. Step 6: Final answer
   x = 391.90