Finding the Third Proportional to 111.50 and 121.13

Step by Step Solution

1. Step 1: Write the proportion equation
   111.50 : 121.13 = 121.13 : x
2. Step 2: Convert to fraction form
   111.50/121.13 = 121.13/x
3. Step 3: Cross multiply
   111.50x = 121.13 × 121.13
4. Step 4: Simplify right side
   111.50x = 14,671.27
5. Step 5: Solve for x
   x = 14,671.27/111.50
6. Step 6: Final answer
   x = 131.58