Finding the Third Proportional to 3,920.27 and 8,489.81

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920.27 : 8,489.81 = 8,489.81 : x
2. Step 2: Convert to fraction form
   3,920.27/8,489.81 = 8,489.81/x
3. Step 3: Cross multiply
   3,920.27x = 8,489.81 × 8,489.81
4. Step 4: Simplify right side
   3,920.27x = 72,076,916.29
5. Step 5: Solve for x
   x = 72,076,916.29/3,920.27
6. Step 6: Final answer
   x = 18,385.69