Finding the Fourth Proportional to 2,518.40, 3,475.35 and 1,399.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,518.40 : 3,475.35 = 1,399.30 : x
2. Step 2: Convert to fraction form
   2,518.40/3,475.35 = 1,399.30/x
3. Step 3: Cross multiply
   2,518.40x = 3,475.35 × 1,399.30
4. Step 4: Simplify right side
   2,518.40x = 4,863,048.57
5. Step 5: Solve for x
   x = 4,863,048.57/2,518.40
6. Step 6: Final answer
   x = 1,931.01