Finding the Fourth Proportional to 2,086.62, 3,128.57 and 852.79

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.62 : 3,128.57 = 852.79 : x
2. Step 2: Convert to fraction form
   2,086.62/3,128.57 = 852.79/x
3. Step 3: Cross multiply
   2,086.62x = 3,128.57 × 852.79
4. Step 4: Simplify right side
   2,086.62x = 2,668,013.21
5. Step 5: Solve for x
   x = 2,668,013.21/2,086.62
6. Step 6: Final answer
   x = 1,278.63