Finding the Fourth Proportional to 12,019.39, 18,028.77 and 5,440.78

Step by Step Solution

1. Step 1: Write the proportion equation
   12,019.39 : 18,028.77 = 5,440.78 : x
2. Step 2: Convert to fraction form
   12,019.39/18,028.77 = 5,440.78/x
3. Step 3: Cross multiply
   12,019.39x = 18,028.77 × 5,440.78
4. Step 4: Simplify right side
   12,019.39x = 98,090,571.24
5. Step 5: Solve for x
   x = 98,090,571.24/12,019.39
6. Step 6: Final answer
   x = 8,161.03