Finding the Fourth Proportional to 3,723.15, 5,139.70 and 2,399.10

Step by Step Solution

1. Step 1: Write the proportion equation
   3,723.15 : 5,139.70 = 2,399.10 : x
2. Step 2: Convert to fraction form
   3,723.15/5,139.70 = 2,399.10/x
3. Step 3: Cross multiply
   3,723.15x = 5,139.70 × 2,399.10
4. Step 4: Simplify right side
   3,723.15x = 12,330,654.27
5. Step 5: Solve for x
   x = 12,330,654.27/3,723.15
6. Step 6: Final answer
   x = 3,311.89