Finding the Fourth Proportional to 2,578.75, 3,558.64 and 1,399.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.75 : 3,558.64 = 1,399.86 : x
2. Step 2: Convert to fraction form
   2,578.75/3,558.64 = 1,399.86/x
3. Step 3: Cross multiply
   2,578.75x = 3,558.64 × 1,399.86
4. Step 4: Simplify right side
   2,578.75x = 4,981,606.69
5. Step 5: Solve for x
   x = 4,981,606.69/2,578.75
6. Step 6: Final answer
   x = 1,931.79