Finding the Fourth Proportional to 2,568.78, 3,544.89 and 1,389.85

Step by Step Solution

1. Step 1: Write the proportion equation
   2,568.78 : 3,544.89 = 1,389.85 : x
2. Step 2: Convert to fraction form
   2,568.78/3,544.89 = 1,389.85/x
3. Step 3: Cross multiply
   2,568.78x = 3,544.89 × 1,389.85
4. Step 4: Simplify right side
   2,568.78x = 4,926,865.37
5. Step 5: Solve for x
   x = 4,926,865.37/2,568.78
6. Step 6: Final answer
   x = 1,917.98