Finding the Third Proportional to 8,578 and 12,758

Step by Step Solution

1. Step 1: Write the proportion equation
   8,578 : 12,758 = 12,758 : x
2. Step 2: Convert to fraction form
   8,578/12,758 = 12,758/x
3. Step 3: Cross multiply
   8,578x = 12,758 × 12,758
4. Step 4: Simplify right side
   8,578x = 162,766,564
5. Step 5: Solve for x
   x = 162,766,564/8,578
6. Step 6: Final answer
   x = 18,974.89