Finding the Fourth Proportional to 1,379.24, 1,904.22 and 855.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.24 : 1,904.22 = 855.57 : x
2. Step 2: Convert to fraction form
   1,379.24/1,904.22 = 855.57/x
3. Step 3: Cross multiply
   1,379.24x = 1,904.22 × 855.57
4. Step 4: Simplify right side
   1,379.24x = 1,629,193.51
5. Step 5: Solve for x
   x = 1,629,193.51/1,379.24
6. Step 6: Final answer
   x = 1,181.23