Finding the Third Proportional to 111.38 and 208.69

Step by Step Solution

1. Step 1: Write the proportion equation
   111.38 : 208.69 = 208.69 : x
2. Step 2: Convert to fraction form
   111.38/208.69 = 208.69/x
3. Step 3: Cross multiply
   111.38x = 208.69 × 208.69
4. Step 4: Simplify right side
   111.38x = 43,550.47
5. Step 5: Solve for x
   x = 43,550.47/111.38
6. Step 6: Final answer
   x = 391.03