Finding the Fourth Proportional to 2,085.58, 3,128.72 and 852.66

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.58 : 3,128.72 = 852.66 : x
2. Step 2: Convert to fraction form
   2,085.58/3,128.72 = 852.66/x
3. Step 3: Cross multiply
   2,085.58x = 3,128.72 × 852.66
4. Step 4: Simplify right side
   2,085.58x = 2,667,730.13
5. Step 5: Solve for x
   x = 2,667,730.13/2,085.58
6. Step 6: Final answer
   x = 1,279.13