Finding the Fourth Proportional to 3,947.10, 5,447.06 and 2,178.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,947.10 : 5,447.06 = 2,178.72 : x
2. Step 2: Convert to fraction form
   3,947.10/5,447.06 = 2,178.72/x
3. Step 3: Cross multiply
   3,947.10x = 5,447.06 × 2,178.72
4. Step 4: Simplify right side
   3,947.10x = 11,867,624.01
5. Step 5: Solve for x
   x = 11,867,624.01/3,947.10
6. Step 6: Final answer
   x = 3,006.67