Finding the Third Proportional to 213.38 and 439.59

Step by Step Solution

1. Step 1: Write the proportion equation
   213.38 : 439.59 = 439.59 : x
2. Step 2: Convert to fraction form
   213.38/439.59 = 439.59/x
3. Step 3: Cross multiply
   213.38x = 439.59 × 439.59
4. Step 4: Simplify right side
   213.38x = 193,242.67
5. Step 5: Solve for x
   x = 193,242.67/213.38
6. Step 6: Final answer
   x = 905.65