Finding the Fourth Proportional to 2,665.85, 3,998.81 and 2,171.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.85 : 3,998.81 = 2,171.69 : x
2. Step 2: Convert to fraction form
   2,665.85/3,998.81 = 2,171.69/x
3. Step 3: Cross multiply
   2,665.85x = 3,998.81 × 2,171.69
4. Step 4: Simplify right side
   2,665.85x = 8,684,144.84
5. Step 5: Solve for x
   x = 8,684,144.84/2,665.85
6. Step 6: Final answer
   x = 3,257.56