Finding the Fourth Proportional to 1,353.50, 1,868.12 and 856.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,353.50 : 1,868.12 = 856.80 : x
2. Step 2: Convert to fraction form
   1,353.50/1,868.12 = 856.80/x
3. Step 3: Cross multiply
   1,353.50x = 1,868.12 × 856.80
4. Step 4: Simplify right side
   1,353.50x = 1,600,608.96
5. Step 5: Solve for x
   x = 1,600,608.96/1,353.50
6. Step 6: Final answer
   x = 1,182.57