Finding the Third Proportional to 31.69 and 68.72

Step by Step Solution

1. Step 1: Write the proportion equation
   31.69 : 68.72 = 68.72 : x
2. Step 2: Convert to fraction form
   31.69/68.72 = 68.72/x
3. Step 3: Cross multiply
   31.69x = 68.72 × 68.72
4. Step 4: Simplify right side
   31.69x = 4,722.27
5. Step 5: Solve for x
   x = 4,722.27/31.69
6. Step 6: Final answer
   x = 149.03