Finding the Fourth Proportional to 1,392.12, 1,921.59 and 894.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.12 : 1,921.59 = 894.78 : x
2. Step 2: Convert to fraction form
   1,392.12/1,921.59 = 894.78/x
3. Step 3: Cross multiply
   1,392.12x = 1,921.59 × 894.78
4. Step 4: Simplify right side
   1,392.12x = 1,719,400.30
5. Step 5: Solve for x
   x = 1,719,400.30/1,392.12
6. Step 6: Final answer
   x = 1,235.09