Finding the Fourth Proportional to 2,085.20, 3,121.56 and 1,260.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.20 : 3,121.56 = 1,260.96 : x
2. Step 2: Convert to fraction form
   2,085.20/3,121.56 = 1,260.96/x
3. Step 3: Cross multiply
   2,085.20x = 3,121.56 × 1,260.96
4. Step 4: Simplify right side
   2,085.20x = 3,936,162.30
5. Step 5: Solve for x
   x = 3,936,162.30/2,085.20
6. Step 6: Final answer
   x = 1,887.67