Finding the Third Proportional to 12,129.75 and 18,518.63

Step by Step Solution

1. Step 1: Write the proportion equation
   12,129.75 : 18,518.63 = 18,518.63 : x
2. Step 2: Convert to fraction form
   12,129.75/18,518.63 = 18,518.63/x
3. Step 3: Cross multiply
   12,129.75x = 18,518.63 × 18,518.63
4. Step 4: Simplify right side
   12,129.75x = 342,939,471.89
5. Step 5: Solve for x
   x = 342,939,471.89/12,129.75
6. Step 6: Final answer
   x = 28,272.59