Finding the Third Proportional to 99 and 142.69

Step by Step Solution

1. Step 1: Write the proportion equation
   99 : 142.69 = 142.69 : x
2. Step 2: Convert to fraction form
   99/142.69 = 142.69/x
3. Step 3: Cross multiply
   99x = 142.69 × 142.69
4. Step 4: Simplify right side
   99x = 20,359.72
5. Step 5: Solve for x
   x = 20,359.72/99
6. Step 6: Final answer
   x = 205.65