Finding the Third Proportional to 221.91 and 395.72

Step by Step Solution

1. Step 1: Write the proportion equation
   221.91 : 395.72 = 395.72 : x
2. Step 2: Convert to fraction form
   221.91/395.72 = 395.72/x
3. Step 3: Cross multiply
   221.91x = 395.72 × 395.72
4. Step 4: Simplify right side
   221.91x = 156,593.33
5. Step 5: Solve for x
   x = 156,593.33/221.91
6. Step 6: Final answer
   x = 705.67