Finding the Third Proportional to 255.56 and 404.81

Step by Step Solution

1. Step 1: Write the proportion equation
   255.56 : 404.81 = 404.81 : x
2. Step 2: Convert to fraction form
   255.56/404.81 = 404.81/x
3. Step 3: Cross multiply
   255.56x = 404.81 × 404.81
4. Step 4: Simplify right side
   255.56x = 163,873.16
5. Step 5: Solve for x
   x = 163,873.16/255.56
6. Step 6: Final answer
   x = 641.23