Finding the Third Proportional to 8,121 and 12,238.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,121 : 12,238.50 = 12,238.50 : x
2. Step 2: Convert to fraction form
   8,121/12,238.50 = 12,238.50/x
3. Step 3: Cross multiply
   8,121x = 12,238.50 × 12,238.50
4. Step 4: Simplify right side
   8,121x = 149,780,882.25
5. Step 5: Solve for x
   x = 149,780,882.25/8,121
6. Step 6: Final answer
   x = 18,443.65