Finding the Fourth Proportional to 2,085.84, 3,128.22 and 853.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.84 : 3,128.22 = 853.02 : x
2. Step 2: Convert to fraction form
   2,085.84/3,128.22 = 853.02/x
3. Step 3: Cross multiply
   2,085.84x = 3,128.22 × 853.02
4. Step 4: Simplify right side
   2,085.84x = 2,668,434.22
5. Step 5: Solve for x
   x = 2,668,434.22/2,085.84
6. Step 6: Final answer
   x = 1,279.31