Finding the Fourth Proportional to 3,979.28, 5,491.46 and 2,211.05

Step by Step Solution

1. Step 1: Write the proportion equation
   3,979.28 : 5,491.46 = 2,211.05 : x
2. Step 2: Convert to fraction form
   3,979.28/5,491.46 = 2,211.05/x
3. Step 3: Cross multiply
   3,979.28x = 5,491.46 × 2,211.05
4. Step 4: Simplify right side
   3,979.28x = 12,141,892.63
5. Step 5: Solve for x
   x = 12,141,892.63/3,979.28
6. Step 6: Final answer
   x = 3,051.28