Finding the Fourth Proportional to 2,588.48, 3,882.56 and 857.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,588.48 : 3,882.56 = 857.28 : x
2. Step 2: Convert to fraction form
   2,588.48/3,882.56 = 857.28/x
3. Step 3: Cross multiply
   2,588.48x = 3,882.56 × 857.28
4. Step 4: Simplify right side
   2,588.48x = 3,328,441.04
5. Step 5: Solve for x
   x = 3,328,441.04/2,588.48
6. Step 6: Final answer
   x = 1,285.87