Finding the Third Proportional to 102.50 and 111.75

Step by Step Solution

1. Step 1: Write the proportion equation
   102.50 : 111.75 = 111.75 : x
2. Step 2: Convert to fraction form
   102.50/111.75 = 111.75/x
3. Step 3: Cross multiply
   102.50x = 111.75 × 111.75
4. Step 4: Simplify right side
   102.50x = 12,488.06
5. Step 5: Solve for x
   x = 12,488.06/102.50
6. Step 6: Final answer
   x = 121.83