Finding the Fourth Proportional to 3,978.81, 5,939.04 and 3,511.79

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.81 : 5,939.04 = 3,511.79 : x
2. Step 2: Convert to fraction form
   3,978.81/5,939.04 = 3,511.79/x
3. Step 3: Cross multiply
   3,978.81x = 5,939.04 × 3,511.79
4. Step 4: Simplify right side
   3,978.81x = 20,856,631.59
5. Step 5: Solve for x
   x = 20,856,631.59/3,978.81
6. Step 6: Final answer
   x = 5,241.93