Finding the Fourth Proportional to 1,380.92, 1,904.73 and 856.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.92 : 1,904.73 = 856.04 : x
2. Step 2: Convert to fraction form
   1,380.92/1,904.73 = 856.04/x
3. Step 3: Cross multiply
   1,380.92x = 1,904.73 × 856.04
4. Step 4: Simplify right side
   1,380.92x = 1,630,525.07
5. Step 5: Solve for x
   x = 1,630,525.07/1,380.92
6. Step 6: Final answer
   x = 1,180.75