Finding the Third Proportional to 9,990 and 17,820

Step by Step Solution

1. Step 1: Write the proportion equation
   9,990 : 17,820 = 17,820 : x
2. Step 2: Convert to fraction form
   9,990/17,820 = 17,820/x
3. Step 3: Cross multiply
   9,990x = 17,820 × 17,820
4. Step 4: Simplify right side
   9,990x = 317,552,400
5. Step 5: Solve for x
   x = 317,552,400/9,990
6. Step 6: Final answer
   x = 31,787.03