Finding the Fourth Proportional to 2,085.61, 3,125.71 and 851.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.61 : 3,125.71 = 851.61 : x
2. Step 2: Convert to fraction form
   2,085.61/3,125.71 = 851.61/x
3. Step 3: Cross multiply
   2,085.61x = 3,125.71 × 851.61
4. Step 4: Simplify right side
   2,085.61x = 2,661,885.89
5. Step 5: Solve for x
   x = 2,661,885.89/2,085.61
6. Step 6: Final answer
   x = 1,276.31