Finding the Fourth Proportional to 12,279.68, 18,418.86 and 3,959.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,279.68 : 18,418.86 = 3,959.50 : x
2. Step 2: Convert to fraction form
   12,279.68/18,418.86 = 3,959.50/x
3. Step 3: Cross multiply
   12,279.68x = 18,418.86 × 3,959.50
4. Step 4: Simplify right side
   12,279.68x = 72,929,476.17
5. Step 5: Solve for x
   x = 72,929,476.17/12,279.68
6. Step 6: Final answer
   x = 5,939.04