Finding the Fourth Proportional to 1,091.86, 1,504.99 and 855.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.86 : 1,504.99 = 855.42 : x
2. Step 2: Convert to fraction form
   1,091.86/1,504.99 = 855.42/x
3. Step 3: Cross multiply
   1,091.86x = 1,504.99 × 855.42
4. Step 4: Simplify right side
   1,091.86x = 1,287,398.55
5. Step 5: Solve for x
   x = 1,287,398.55/1,091.86
6. Step 6: Final answer
   x = 1,179.09