Finding the Third Proportional to 260.72 and 398.81

Step by Step Solution

1. Step 1: Write the proportion equation
   260.72 : 398.81 = 398.81 : x
2. Step 2: Convert to fraction form
   260.72/398.81 = 398.81/x
3. Step 3: Cross multiply
   260.72x = 398.81 × 398.81
4. Step 4: Simplify right side
   260.72x = 159,051.41
5. Step 5: Solve for x
   x = 159,051.41/260.72
6. Step 6: Final answer
   x = 610.05