Finding the Fourth Proportional to 1,383.10, 1,908.89 and 912.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,383.10 : 1,908.89 = 912.36 : x
2. Step 2: Convert to fraction form
   1,383.10/1,908.89 = 912.36/x
3. Step 3: Cross multiply
   1,383.10x = 1,908.89 × 912.36
4. Step 4: Simplify right side
   1,383.10x = 1,741,594.88
5. Step 5: Solve for x
   x = 1,741,594.88/1,383.10
6. Step 6: Final answer
   x = 1,259.20