Finding the Fourth Proportional to 5,439.57, 8,158.28 and 2,665.05

Step by Step Solution

1. Step 1: Write the proportion equation
   5,439.57 : 8,158.28 = 2,665.05 : x
2. Step 2: Convert to fraction form
   5,439.57/8,158.28 = 2,665.05/x
3. Step 3: Cross multiply
   5,439.57x = 8,158.28 × 2,665.05
4. Step 4: Simplify right side
   5,439.57x = 21,742,210.79
5. Step 5: Solve for x
   x = 21,742,210.79/5,439.57
6. Step 6: Final answer
   x = 3,997.05