Finding the Fourth Proportional to 1,383.98, 1,910.51 and 912.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,383.98 : 1,910.51 = 912.12 : x
2. Step 2: Convert to fraction form
   1,383.98/1,910.51 = 912.12/x
3. Step 3: Cross multiply
   1,383.98x = 1,910.51 × 912.12
4. Step 4: Simplify right side
   1,383.98x = 1,742,609.82
5. Step 5: Solve for x
   x = 1,742,609.82/1,383.98
6. Step 6: Final answer
   x = 1,259.13