Finding the Third Proportional to 30,680 and 71,688

Step by Step Solution

1. Step 1: Write the proportion equation
   30,680 : 71,688 = 71,688 : x
2. Step 2: Convert to fraction form
   30,680/71,688 = 71,688/x
3. Step 3: Cross multiply
   30,680x = 71,688 × 71,688
4. Step 4: Simplify right side
   30,680x = 5,139,169,344
5. Step 5: Solve for x
   x = 5,139,169,344/30,680
6. Step 6: Final answer
   x = 167,508.78