Finding the Fourth Proportional to 12,820, 19,233.42 and 5,424.78

Step by Step Solution

1. Step 1: Write the proportion equation
   12,820 : 19,233.42 = 5,424.78 : x
2. Step 2: Convert to fraction form
   12,820/19,233.42 = 5,424.78/x
3. Step 3: Cross multiply
   12,820x = 19,233.42 × 5,424.78
4. Step 4: Simplify right side
   12,820x = 104,337,072.15
5. Step 5: Solve for x
   x = 104,337,072.15/12,820
6. Step 6: Final answer
   x = 8,138.62