Finding the Third Proportional to 121.50 and 231.61

Step by Step Solution

1. Step 1: Write the proportion equation
   121.50 : 231.61 = 231.61 : x
2. Step 2: Convert to fraction form
   121.50/231.61 = 231.61/x
3. Step 3: Cross multiply
   121.50x = 231.61 × 231.61
4. Step 4: Simplify right side
   121.50x = 53,642.90
5. Step 5: Solve for x
   x = 53,642.90/121.50
6. Step 6: Final answer
   x = 441.51