Finding the Third Proportional to 216.28 and 404.72

Step by Step Solution

1. Step 1: Write the proportion equation
   216.28 : 404.72 = 404.72 : x
2. Step 2: Convert to fraction form
   216.28/404.72 = 404.72/x
3. Step 3: Cross multiply
   216.28x = 404.72 × 404.72
4. Step 4: Simplify right side
   216.28x = 163,797.27
5. Step 5: Solve for x
   x = 163,797.27/216.28
6. Step 6: Final answer
   x = 757.33