Finding the Third Proportional to 102.88 and 213.38

Step by Step Solution

1. Step 1: Write the proportion equation
   102.88 : 213.38 = 213.38 : x
2. Step 2: Convert to fraction form
   102.88/213.38 = 213.38/x
3. Step 3: Cross multiply
   102.88x = 213.38 × 213.38
4. Step 4: Simplify right side
   102.88x = 45,528.89
5. Step 5: Solve for x
   x = 45,528.89/102.88
6. Step 6: Final answer
   x = 442.57