Finding the Fourth Proportional to 1,555.88, 2,147.15 and 857.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,555.88 : 2,147.15 = 857.30 : x
2. Step 2: Convert to fraction form
   1,555.88/2,147.15 = 857.30/x
3. Step 3: Cross multiply
   1,555.88x = 2,147.15 × 857.30
4. Step 4: Simplify right side
   1,555.88x = 1,840,743.10
5. Step 5: Solve for x
   x = 1,840,743.10/1,555.88
6. Step 6: Final answer
   x = 1,183.09