Finding the Third Proportional to 144.28 and 213.89

Step by Step Solution

1. Step 1: Write the proportion equation
   144.28 : 213.89 = 213.89 : x
2. Step 2: Convert to fraction form
   144.28/213.89 = 213.89/x
3. Step 3: Cross multiply
   144.28x = 213.89 × 213.89
4. Step 4: Simplify right side
   144.28x = 45,749.20
5. Step 5: Solve for x
   x = 45,749.20/144.28
6. Step 6: Final answer
   x = 317.08