Finding the Fourth Proportional to 12,061.72, 18,078.62 and 7,135.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,061.72 : 18,078.62 = 7,135.50 : x
2. Step 2: Convert to fraction form
   12,061.72/18,078.62 = 7,135.50/x
3. Step 3: Cross multiply
   12,061.72x = 18,078.62 × 7,135.50
4. Step 4: Simplify right side
   12,061.72x = 128,999,993.01
5. Step 5: Solve for x
   x = 128,999,993.01/12,061.72
6. Step 6: Final answer
   x = 10,694.99