Finding the Third Proportional to 8,721 and 13,140

Step by Step Solution

1. Step 1: Write the proportion equation
   8,721 : 13,140 = 13,140 : x
2. Step 2: Convert to fraction form
   8,721/13,140 = 13,140/x
3. Step 3: Cross multiply
   8,721x = 13,140 × 13,140
4. Step 4: Simplify right side
   8,721x = 172,659,600
5. Step 5: Solve for x
   x = 172,659,600/8,721
6. Step 6: Final answer
   x = 19,798.14