Finding the Third Proportional to 127.69 and 278.81

Step by Step Solution

1. Step 1: Write the proportion equation
   127.69 : 278.81 = 278.81 : x
2. Step 2: Convert to fraction form
   127.69/278.81 = 278.81/x
3. Step 3: Cross multiply
   127.69x = 278.81 × 278.81
4. Step 4: Simplify right side
   127.69x = 77,736.41
5. Step 5: Solve for x
   x = 77,736.41/127.69
6. Step 6: Final answer
   x = 608.80