Finding the Third Proportional to 127.20 and 300.90

Step by Step Solution

1. Step 1: Write the proportion equation
   127.20 : 300.90 = 300.90 : x
2. Step 2: Convert to fraction form
   127.20/300.90 = 300.90/x
3. Step 3: Cross multiply
   127.20x = 300.90 × 300.90
4. Step 4: Simplify right side
   127.20x = 90,542.22
5. Step 5: Solve for x
   x = 90,542.22/127.20
6. Step 6: Final answer
   x = 711.84