Finding the Third Proportional to 128.25 and 155.25

Step by Step Solution

1. Step 1: Write the proportion equation
   128.25 : 155.25 = 155.25 : x
2. Step 2: Convert to fraction form
   128.25/155.25 = 155.25/x
3. Step 3: Cross multiply
   128.25x = 155.25 × 155.25
4. Step 4: Simplify right side
   128.25x = 24,102.56
5. Step 5: Solve for x
   x = 24,102.56/128.25
6. Step 6: Final answer
   x = 187.93