Finding the Third Proportional to 128 and 168.38

Step by Step Solution

1. Step 1: Write the proportion equation
   128 : 168.38 = 168.38 : x
2. Step 2: Convert to fraction form
   128/168.38 = 168.38/x
3. Step 3: Cross multiply
   128x = 168.38 × 168.38
4. Step 4: Simplify right side
   128x = 28,350.14
5. Step 5: Solve for x
   x = 28,350.14/128
6. Step 6: Final answer
   x = 221.49