Finding the Third Proportional to 111.50 and 259

Step by Step Solution

1. Step 1: Write the proportion equation
   111.50 : 259 = 259 : x
2. Step 2: Convert to fraction form
   111.50/259 = 259/x
3. Step 3: Cross multiply
   111.50x = 259 × 259
4. Step 4: Simplify right side
   111.50x = 67,081
5. Step 5: Solve for x
   x = 67,081/111.50
6. Step 6: Final answer
   x = 601.62