Finding the Fourth Proportional to 12,279.30, 18,419.40 and 3,959.43

Step by Step Solution

1. Step 1: Write the proportion equation
   12,279.30 : 18,419.40 = 3,959.43 : x
2. Step 2: Convert to fraction form
   12,279.30/18,419.40 = 3,959.43/x
3. Step 3: Cross multiply
   12,279.30x = 18,419.40 × 3,959.43
4. Step 4: Simplify right side
   12,279.30x = 72,930,255.87
5. Step 5: Solve for x
   x = 72,930,255.87/12,279.30
6. Step 6: Final answer
   x = 5,939.29