Finding the Fourth Proportional to 1,443.42, 1,991.25 and 912.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.42 : 1,991.25 = 912.06 : x
2. Step 2: Convert to fraction form
   1,443.42/1,991.25 = 912.06/x
3. Step 3: Cross multiply
   1,443.42x = 1,991.25 × 912.06
4. Step 4: Simplify right side
   1,443.42x = 1,816,139.48
5. Step 5: Solve for x
   x = 1,816,139.48/1,443.42
6. Step 6: Final answer
   x = 1,258.22