Finding the Third Proportional to 124.78 and 221.72

Step by Step Solution

1. Step 1: Write the proportion equation
   124.78 : 221.72 = 221.72 : x
2. Step 2: Convert to fraction form
   124.78/221.72 = 221.72/x
3. Step 3: Cross multiply
   124.78x = 221.72 × 221.72
4. Step 4: Simplify right side
   124.78x = 49,159.20
5. Step 5: Solve for x
   x = 49,159.20/124.78
6. Step 6: Final answer
   x = 393.96