Finding the Fourth Proportional to 1,445.10, 1,993.60 and 855.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,445.10 : 1,993.60 = 855.30 : x
2. Step 2: Convert to fraction form
   1,445.10/1,993.60 = 855.30/x
3. Step 3: Cross multiply
   1,445.10x = 1,993.60 × 855.30
4. Step 4: Simplify right side
   1,445.10x = 1,705,126.08
5. Step 5: Solve for x
   x = 1,705,126.08/1,445.10
6. Step 6: Final answer
   x = 1,179.94