Finding the Fourth Proportional to 1,563.90, 2,158.17 and 855.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,563.90 : 2,158.17 = 855.72 : x
2. Step 2: Convert to fraction form
   1,563.90/2,158.17 = 855.72/x
3. Step 3: Cross multiply
   1,563.90x = 2,158.17 × 855.72
4. Step 4: Simplify right side
   1,563.90x = 1,846,789.23
5. Step 5: Solve for x
   x = 1,846,789.23/1,563.90
6. Step 6: Final answer
   x = 1,180.89