Finding the Fourth Proportional to 1,353.11, 1,866.94 and 856.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,353.11 : 1,866.94 = 856.31 : x
2. Step 2: Convert to fraction form
   1,353.11/1,866.94 = 856.31/x
3. Step 3: Cross multiply
   1,353.11x = 1,866.94 × 856.31
4. Step 4: Simplify right side
   1,353.11x = 1,598,667.92
5. Step 5: Solve for x
   x = 1,598,667.92/1,353.11
6. Step 6: Final answer
   x = 1,181.48