Finding the Fourth Proportional to 2,721.06, 4,081.55 and 872.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,721.06 : 4,081.55 = 872.15 : x
2. Step 2: Convert to fraction form
   2,721.06/4,081.55 = 872.15/x
3. Step 3: Cross multiply
   2,721.06x = 4,081.55 × 872.15
4. Step 4: Simplify right side
   2,721.06x = 3,559,699.06
5. Step 5: Solve for x
   x = 3,559,699.06/2,721.06
6. Step 6: Final answer
   x = 1,308.20