Finding the Third Proportional to 8,129 and 12,021.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,129 : 12,021.50 = 12,021.50 : x
2. Step 2: Convert to fraction form
   8,129/12,021.50 = 12,021.50/x
3. Step 3: Cross multiply
   8,129x = 12,021.50 × 12,021.50
4. Step 4: Simplify right side
   8,129x = 144,516,462.25
5. Step 5: Solve for x
   x = 144,516,462.25/8,129
6. Step 6: Final answer
   x = 17,777.89