Finding the Fourth Proportional to 2,086.06, 3,130.30 and 853.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.06 : 3,130.30 = 853.28 : x
2. Step 2: Convert to fraction form
   2,086.06/3,130.30 = 853.28/x
3. Step 3: Cross multiply
   2,086.06x = 3,130.30 × 853.28
4. Step 4: Simplify right side
   2,086.06x = 2,671,022.38
5. Step 5: Solve for x
   x = 2,671,022.38/2,086.06
6. Step 6: Final answer
   x = 1,280.41