Finding the Third Proportional to 8,000 and 10,400

Step by Step Solution

1. Step 1: Write the proportion equation
   8,000 : 10,400 = 10,400 : x
2. Step 2: Convert to fraction form
   8,000/10,400 = 10,400/x
3. Step 3: Cross multiply
   8,000x = 10,400 × 10,400
4. Step 4: Simplify right side
   8,000x = 108,160,000
5. Step 5: Solve for x
   x = 108,160,000/8,000
6. Step 6: Final answer
   x = 13,520