Finding the Third Proportional to 15,684 and 21,510

Step by Step Solution

1. Step 1: Write the proportion equation
   15,684 : 21,510 = 21,510 : x
2. Step 2: Convert to fraction form
   15,684/21,510 = 21,510/x
3. Step 3: Cross multiply
   15,684x = 21,510 × 21,510
4. Step 4: Simplify right side
   15,684x = 462,680,100
5. Step 5: Solve for x
   x = 462,680,100/15,684
6. Step 6: Final answer
   x = 29,500.13