Finding the Fourth Proportional to 2,399.86, 3,311.31 and 1,515.17

Step by Step Solution

1. Step 1: Write the proportion equation
   2,399.86 : 3,311.31 = 1,515.17 : x
2. Step 2: Convert to fraction form
   2,399.86/3,311.31 = 1,515.17/x
3. Step 3: Cross multiply
   2,399.86x = 3,311.31 × 1,515.17
4. Step 4: Simplify right side
   2,399.86x = 5,017,211.53
5. Step 5: Solve for x
   x = 5,017,211.53/2,399.86
6. Step 6: Final answer
   x = 2,090.63