Finding the Third Proportional to 4,990 and 10,268

Step by Step Solution

1. Step 1: Write the proportion equation
   4,990 : 10,268 = 10,268 : x
2. Step 2: Convert to fraction form
   4,990/10,268 = 10,268/x
3. Step 3: Cross multiply
   4,990x = 10,268 × 10,268
4. Step 4: Simplify right side
   4,990x = 105,431,824
5. Step 5: Solve for x
   x = 105,431,824/4,990
6. Step 6: Final answer
   x = 21,128.62