Finding the Fourth Proportional to 2,578.50, 3,555.01 and 2,105.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.50 : 3,555.01 = 2,105.90 : x
2. Step 2: Convert to fraction form
   2,578.50/3,555.01 = 2,105.90/x
3. Step 3: Cross multiply
   2,578.50x = 3,555.01 × 2,105.90
4. Step 4: Simplify right side
   2,578.50x = 7,486,472.52
5. Step 5: Solve for x
   x = 7,486,472.52/2,578.50
6. Step 6: Final answer
   x = 2,903.42