Finding the Third Proportional to 12,811.50 and 19,872

Step by Step Solution

1. Step 1: Write the proportion equation
   12,811.50 : 19,872 = 19,872 : x
2. Step 2: Convert to fraction form
   12,811.50/19,872 = 19,872/x
3. Step 3: Cross multiply
   12,811.50x = 19,872 × 19,872
4. Step 4: Simplify right side
   12,811.50x = 394,896,384
5. Step 5: Solve for x
   x = 394,896,384/12,811.50
6. Step 6: Final answer
   x = 30,823.59