Finding the Fourth Proportional to 3,971.89, 5,480.42 and 2,399.99

Step by Step Solution

1. Step 1: Write the proportion equation
   3,971.89 : 5,480.42 = 2,399.99 : x
2. Step 2: Convert to fraction form
   3,971.89/5,480.42 = 2,399.99/x
3. Step 3: Cross multiply
   3,971.89x = 5,480.42 × 2,399.99
4. Step 4: Simplify right side
   3,971.89x = 13,152,913.79
5. Step 5: Solve for x
   x = 13,152,913.79/3,971.89
6. Step 6: Final answer
   x = 3,311.50