Finding the Third Proportional to 10,521 and 21,339

Step by Step Solution

1. Step 1: Write the proportion equation
   10,521 : 21,339 = 21,339 : x
2. Step 2: Convert to fraction form
   10,521/21,339 = 21,339/x
3. Step 3: Cross multiply
   10,521x = 21,339 × 21,339
4. Step 4: Simplify right side
   10,521x = 455,352,921
5. Step 5: Solve for x
   x = 455,352,921/10,521
6. Step 6: Final answer
   x = 43,280.38