Finding the Fourth Proportional to 2,578.46, 3,558.34 and 1,399.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.46 : 3,558.34 = 1,399.60 : x
2. Step 2: Convert to fraction form
   2,578.46/3,558.34 = 1,399.60/x
3. Step 3: Cross multiply
   2,578.46x = 3,558.34 × 1,399.60
4. Step 4: Simplify right side
   2,578.46x = 4,980,258.86
5. Step 5: Solve for x
   x = 4,980,258.86/2,578.46
6. Step 6: Final answer
   x = 1,931.49