Finding the Third Proportional to 109.69 and 238.78

Step by Step Solution

1. Step 1: Write the proportion equation
   109.69 : 238.78 = 238.78 : x
2. Step 2: Convert to fraction form
   109.69/238.78 = 238.78/x
3. Step 3: Cross multiply
   109.69x = 238.78 × 238.78
4. Step 4: Simplify right side
   109.69x = 57,016.49
5. Step 5: Solve for x
   x = 57,016.49/109.69
6. Step 6: Final answer
   x = 519.81