Finding the Third Proportional to 51.72 and 127.78

Step by Step Solution

1. Step 1: Write the proportion equation
   51.72 : 127.78 = 127.78 : x
2. Step 2: Convert to fraction form
   51.72/127.78 = 127.78/x
3. Step 3: Cross multiply
   51.72x = 127.78 × 127.78
4. Step 4: Simplify right side
   51.72x = 16,328.05
5. Step 5: Solve for x
   x = 16,328.05/51.72
6. Step 6: Final answer
   x = 315.71