Finding the Third Proportional to 8,208 and 12,915

Step by Step Solution

1. Step 1: Write the proportion equation
   8,208 : 12,915 = 12,915 : x
2. Step 2: Convert to fraction form
   8,208/12,915 = 12,915/x
3. Step 3: Cross multiply
   8,208x = 12,915 × 12,915
4. Step 4: Simplify right side
   8,208x = 166,797,225
5. Step 5: Solve for x
   x = 166,797,225/8,208
6. Step 6: Final answer
   x = 20,321.30