Finding the Fourth Proportional to 2,578.50, 3,558.33 and 1,399.58

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.50 : 3,558.33 = 1,399.58 : x
2. Step 2: Convert to fraction form
   2,578.50/3,558.33 = 1,399.58/x
3. Step 3: Cross multiply
   2,578.50x = 3,558.33 × 1,399.58
4. Step 4: Simplify right side
   2,578.50x = 4,980,163.05
5. Step 5: Solve for x
   x = 4,980,163.05/2,578.50
6. Step 6: Final answer
   x = 1,931.42