Finding the Third Proportional to 9,690 and 21,128

Step by Step Solution

1. Step 1: Write the proportion equation
   9,690 : 21,128 = 21,128 : x
2. Step 2: Convert to fraction form
   9,690/21,128 = 21,128/x
3. Step 3: Cross multiply
   9,690x = 21,128 × 21,128
4. Step 4: Simplify right side
   9,690x = 446,392,384
5. Step 5: Solve for x
   x = 446,392,384/9,690
6. Step 6: Final answer
   x = 46,067.33