Finding the Fourth Proportional to 1,581.28, 2,367.42 and 839.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,581.28 : 2,367.42 = 839.20 : x
2. Step 2: Convert to fraction form
   1,581.28/2,367.42 = 839.20/x
3. Step 3: Cross multiply
   1,581.28x = 2,367.42 × 839.20
4. Step 4: Simplify right side
   1,581.28x = 1,986,738.86
5. Step 5: Solve for x
   x = 1,986,738.86/1,581.28
6. Step 6: Final answer
   x = 1,256.41