Finding the Third Proportional to 9,990 and 13,557

Step by Step Solution

1. Step 1: Write the proportion equation
   9,990 : 13,557 = 13,557 : x
2. Step 2: Convert to fraction form
   9,990/13,557 = 13,557/x
3. Step 3: Cross multiply
   9,990x = 13,557 × 13,557
4. Step 4: Simplify right side
   9,990x = 183,792,249
5. Step 5: Solve for x
   x = 183,792,249/9,990
6. Step 6: Final answer
   x = 18,397.62