Finding the Fourth Proportional to 12,443.29, 17,172.47 and 7,139.81

Step by Step Solution

1. Step 1: Write the proportion equation
   12,443.29 : 17,172.47 = 7,139.81 : x
2. Step 2: Convert to fraction form
   12,443.29/17,172.47 = 7,139.81/x
3. Step 3: Cross multiply
   12,443.29x = 17,172.47 × 7,139.81
4. Step 4: Simplify right side
   12,443.29x = 122,608,233.81
5. Step 5: Solve for x
   x = 122,608,233.81/12,443.29
6. Step 6: Final answer
   x = 9,853.36