Finding the Fourth Proportional to 1,298.17, 1,789.86 and 855.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.17 : 1,789.86 = 855.37 : x
2. Step 2: Convert to fraction form
   1,298.17/1,789.86 = 855.37/x
3. Step 3: Cross multiply
   1,298.17x = 1,789.86 × 855.37
4. Step 4: Simplify right side
   1,298.17x = 1,530,992.55
5. Step 5: Solve for x
   x = 1,530,992.55/1,298.17
6. Step 6: Final answer
   x = 1,179.35