Finding the Third Proportional to 16,217 and 20,721.50

Step by Step Solution

1. Step 1: Write the proportion equation
   16,217 : 20,721.50 = 20,721.50 : x
2. Step 2: Convert to fraction form
   16,217/20,721.50 = 20,721.50/x
3. Step 3: Cross multiply
   16,217x = 20,721.50 × 20,721.50
4. Step 4: Simplify right side
   16,217x = 429,380,562.25
5. Step 5: Solve for x
   x = 429,380,562.25/16,217
6. Step 6: Final answer
   x = 26,477.19