Finding the Third Proportional to 10,698 and 21,990

Step by Step Solution

1. Step 1: Write the proportion equation
   10,698 : 21,990 = 21,990 : x
2. Step 2: Convert to fraction form
   10,698/21,990 = 21,990/x
3. Step 3: Cross multiply
   10,698x = 21,990 × 21,990
4. Step 4: Simplify right side
   10,698x = 483,560,100
5. Step 5: Solve for x
   x = 483,560,100/10,698
6. Step 6: Final answer
   x = 45,200.98