Finding the Third Proportional to 8,440 and 13,040

Step by Step Solution

1. Step 1: Write the proportion equation
   8,440 : 13,040 = 13,040 : x
2. Step 2: Convert to fraction form
   8,440/13,040 = 13,040/x
3. Step 3: Cross multiply
   8,440x = 13,040 × 13,040
4. Step 4: Simplify right side
   8,440x = 170,041,600
5. Step 5: Solve for x
   x = 170,041,600/8,440
6. Step 6: Final answer
   x = 20,147.11