Finding the Third Proportional to 7,990 and 12,648

Step by Step Solution

1. Step 1: Write the proportion equation
   7,990 : 12,648 = 12,648 : x
2. Step 2: Convert to fraction form
   7,990/12,648 = 12,648/x
3. Step 3: Cross multiply
   7,990x = 12,648 × 12,648
4. Step 4: Simplify right side
   7,990x = 159,971,904
5. Step 5: Solve for x
   x = 159,971,904/7,990
6. Step 6: Final answer
   x = 20,021.51