Finding the Third Proportional to 31.72 and 69.63

Step by Step Solution

1. Step 1: Write the proportion equation
   31.72 : 69.63 = 69.63 : x
2. Step 2: Convert to fraction form
   31.72/69.63 = 69.63/x
3. Step 3: Cross multiply
   31.72x = 69.63 × 69.63
4. Step 4: Simplify right side
   31.72x = 4,847.64
5. Step 5: Solve for x
   x = 4,847.64/31.72
6. Step 6: Final answer
   x = 152.83