Finding the Third Proportional to 12,109 and 18,515.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,109 : 18,515.50 = 18,515.50 : x
2. Step 2: Convert to fraction form
   12,109/18,515.50 = 18,515.50/x
3. Step 3: Cross multiply
   12,109x = 18,515.50 × 18,515.50
4. Step 4: Simplify right side
   12,109x = 342,823,740.25
5. Step 5: Solve for x
   x = 342,823,740.25/12,109
6. Step 6: Final answer
   x = 28,311.48