Finding the Third Proportional to 111.38 and 261.56

Step by Step Solution

1. Step 1: Write the proportion equation
   111.38 : 261.56 = 261.56 : x
2. Step 2: Convert to fraction form
   111.38/261.56 = 261.56/x
3. Step 3: Cross multiply
   111.38x = 261.56 × 261.56
4. Step 4: Simplify right side
   111.38x = 68,414.94
5. Step 5: Solve for x
   x = 68,414.94/111.38
6. Step 6: Final answer
   x = 614.28