Finding the Fourth Proportional to 2,641.41, 3,961.31 and 2,120.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,641.41 : 3,961.31 = 2,120.18 : x
2. Step 2: Convert to fraction form
   2,641.41/3,961.31 = 2,120.18/x
3. Step 3: Cross multiply
   2,641.41x = 3,961.31 × 2,120.18
4. Step 4: Simplify right side
   2,641.41x = 8,398,659.83
5. Step 5: Solve for x
   x = 8,398,659.83/2,641.41
6. Step 6: Final answer
   x = 3,179.61