Finding the Third Proportional to 111.77 and 239.38

Step by Step Solution

1. Step 1: Write the proportion equation
   111.77 : 239.38 = 239.38 : x
2. Step 2: Convert to fraction form
   111.77/239.38 = 239.38/x
3. Step 3: Cross multiply
   111.77x = 239.38 × 239.38
4. Step 4: Simplify right side
   111.77x = 57,303.31
5. Step 5: Solve for x
   x = 57,303.31/111.77
6. Step 6: Final answer
   x = 512.69