Finding the Fourth Proportional to 2,085.61, 3,129.95 and 1,679.65

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.61 : 3,129.95 = 1,679.65 : x
2. Step 2: Convert to fraction form
   2,085.61/3,129.95 = 1,679.65/x
3. Step 3: Cross multiply
   2,085.61x = 3,129.95 × 1,679.65
4. Step 4: Simplify right side
   2,085.61x = 5,257,216.89
5. Step 5: Solve for x
   x = 5,257,216.89/2,085.61
6. Step 6: Final answer
   x = 2,520.71