Finding the Third Proportional to 11,671.50 and 15,724.50

Step by Step Solution

1. Step 1: Write the proportion equation
   11,671.50 : 15,724.50 = 15,724.50 : x
2. Step 2: Convert to fraction form
   11,671.50/15,724.50 = 15,724.50/x
3. Step 3: Cross multiply
   11,671.50x = 15,724.50 × 15,724.50
4. Step 4: Simplify right side
   11,671.50x = 247,259,900.25
5. Step 5: Solve for x
   x = 247,259,900.25/11,671.50
6. Step 6: Final answer
   x = 21,184.93