Finding the Fourth Proportional to 2,086.56, 3,128.03 and 853.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.56 : 3,128.03 = 853.18 : x
2. Step 2: Convert to fraction form
   2,086.56/3,128.03 = 853.18/x
3. Step 3: Cross multiply
   2,086.56x = 3,128.03 × 853.18
4. Step 4: Simplify right side
   2,086.56x = 2,668,772.64
5. Step 5: Solve for x
   x = 2,668,772.64/2,086.56
6. Step 6: Final answer
   x = 1,279.03