Finding the Third Proportional to 31.80 and 70.72

Step by Step Solution

1. Step 1: Write the proportion equation
   31.80 : 70.72 = 70.72 : x
2. Step 2: Convert to fraction form
   31.80/70.72 = 70.72/x
3. Step 3: Cross multiply
   31.80x = 70.72 × 70.72
4. Step 4: Simplify right side
   31.80x = 5,000.87
5. Step 5: Solve for x
   x = 5,000.87/31.80
6. Step 6: Final answer
   x = 157.27