Finding the Fourth Proportional to 39,142.59, 58,718.45 and 12,479.28

Step by Step Solution

1. Step 1: Write the proportion equation
   39,142.59 : 58,718.45 = 12,479.28 : x
2. Step 2: Convert to fraction form
   39,142.59/58,718.45 = 12,479.28/x
3. Step 3: Cross multiply
   39,142.59x = 58,718.45 × 12,479.28
4. Step 4: Simplify right side
   39,142.59x = 732,763,789.72
5. Step 5: Solve for x
   x = 732,763,789.72/39,142.59
6. Step 6: Final answer
   x = 18,720.37