Finding the Fourth Proportional to 3,977.89, 5,489.15 and 2,185.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,977.89 : 5,489.15 = 2,185.31 : x
2. Step 2: Convert to fraction form
   3,977.89/5,489.15 = 2,185.31/x
3. Step 3: Cross multiply
   3,977.89x = 5,489.15 × 2,185.31
4. Step 4: Simplify right side
   3,977.89x = 11,995,513.57
5. Step 5: Solve for x
   x = 11,995,513.57/3,977.89
6. Step 6: Final answer
   x = 3,015.55