Finding the Fourth Proportional to 2,561.42, 3,839.01 and 1,328.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.42 : 3,839.01 = 1,328.15 : x
2. Step 2: Convert to fraction form
   2,561.42/3,839.01 = 1,328.15/x
3. Step 3: Cross multiply
   2,561.42x = 3,839.01 × 1,328.15
4. Step 4: Simplify right side
   2,561.42x = 5,098,781.13
5. Step 5: Solve for x
   x = 5,098,781.13/2,561.42
6. Step 6: Final answer
   x = 1,990.61