Finding the Fourth Proportional to 2,561.69, 3,839.37 and 1,328.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.69 : 3,839.37 = 1,328.39 : x
2. Step 2: Convert to fraction form
   2,561.69/3,839.37 = 1,328.39/x
3. Step 3: Cross multiply
   2,561.69x = 3,839.37 × 1,328.39
4. Step 4: Simplify right side
   2,561.69x = 5,100,180.71
5. Step 5: Solve for x
   x = 5,100,180.71/2,561.69
6. Step 6: Final answer
   x = 1,990.94