Finding the Third Proportional to 6,404 and 12,790

Step by Step Solution

1. Step 1: Write the proportion equation
   6,404 : 12,790 = 12,790 : x
2. Step 2: Convert to fraction form
   6,404/12,790 = 12,790/x
3. Step 3: Cross multiply
   6,404x = 12,790 × 12,790
4. Step 4: Simplify right side
   6,404x = 163,584,100
5. Step 5: Solve for x
   x = 163,584,100/6,404
6. Step 6: Final answer
   x = 25,544.05