Finding the Third Proportional to 142.88 and 221.25

Step by Step Solution

1. Step 1: Write the proportion equation
   142.88 : 221.25 = 221.25 : x
2. Step 2: Convert to fraction form
   142.88/221.25 = 221.25/x
3. Step 3: Cross multiply
   142.88x = 221.25 × 221.25
4. Step 4: Simplify right side
   142.88x = 48,951.56
5. Step 5: Solve for x
   x = 48,951.56/142.88
6. Step 6: Final answer
   x = 342.62