Finding the Fourth Proportional to 2,086.12, 3,128.13 and 853.03

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.12 : 3,128.13 = 853.03 : x
2. Step 2: Convert to fraction form
   2,086.12/3,128.13 = 853.03/x
3. Step 3: Cross multiply
   2,086.12x = 3,128.13 × 853.03
4. Step 4: Simplify right side
   2,086.12x = 2,668,388.73
5. Step 5: Solve for x
   x = 2,668,388.73/2,086.12
6. Step 6: Final answer
   x = 1,279.12