Finding the Fourth Proportional to 2,721.78, 4,080.67 and 871.83

Step by Step Solution

1. Step 1: Write the proportion equation
   2,721.78 : 4,080.67 = 871.83 : x
2. Step 2: Convert to fraction form
   2,721.78/4,080.67 = 871.83/x
3. Step 3: Cross multiply
   2,721.78x = 4,080.67 × 871.83
4. Step 4: Simplify right side
   2,721.78x = 3,557,650.53
5. Step 5: Solve for x
   x = 3,557,650.53/2,721.78
6. Step 6: Final answer
   x = 1,307.10