Finding the Third Proportional to 123 and 142.50

Step by Step Solution

1. Step 1: Write the proportion equation
   123 : 142.50 = 142.50 : x
2. Step 2: Convert to fraction form
   123/142.50 = 142.50/x
3. Step 3: Cross multiply
   123x = 142.50 × 142.50
4. Step 4: Simplify right side
   123x = 20,306.25
5. Step 5: Solve for x
   x = 20,306.25/123
6. Step 6: Final answer
   x = 165.09