Finding the Third Proportional to 64.50 and 142.69

Step by Step Solution

1. Step 1: Write the proportion equation
   64.50 : 142.69 = 142.69 : x
2. Step 2: Convert to fraction form
   64.50/142.69 = 142.69/x
3. Step 3: Cross multiply
   64.50x = 142.69 × 142.69
4. Step 4: Simplify right side
   64.50x = 20,359.72
5. Step 5: Solve for x
   x = 20,359.72/64.50
6. Step 6: Final answer
   x = 315.65