Finding the Fourth Proportional to 1,298.33, 1,791.72 and 857.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.33 : 1,791.72 = 857.05 : x
2. Step 2: Convert to fraction form
   1,298.33/1,791.72 = 857.05/x
3. Step 3: Cross multiply
   1,298.33x = 1,791.72 × 857.05
4. Step 4: Simplify right side
   1,298.33x = 1,535,589.15
5. Step 5: Solve for x
   x = 1,535,589.15/1,298.33
6. Step 6: Final answer
   x = 1,182.74