Finding the Fourth Proportional to 1,557.45, 2,149.31 and 858.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,557.45 : 2,149.31 = 858.83 : x
2. Step 2: Convert to fraction form
   1,557.45/2,149.31 = 858.83/x
3. Step 3: Cross multiply
   1,557.45x = 2,149.31 × 858.83
4. Step 4: Simplify right side
   1,557.45x = 1,845,891.91
5. Step 5: Solve for x
   x = 1,845,891.91/1,557.45
6. Step 6: Final answer
   x = 1,185.20