Finding the Fourth Proportional to 12,139.38, 18,210.38 and 3,819.65

Step by Step Solution

1. Step 1: Write the proportion equation
   12,139.38 : 18,210.38 = 3,819.65 : x
2. Step 2: Convert to fraction form
   12,139.38/18,210.38 = 3,819.65/x
3. Step 3: Cross multiply
   12,139.38x = 18,210.38 × 3,819.65
4. Step 4: Simplify right side
   12,139.38x = 69,557,167.82
5. Step 5: Solve for x
   x = 69,557,167.82/12,139.38
6. Step 6: Final answer
   x = 5,729.88