Finding the Fourth Proportional to 1,443.54, 1,991.60 and 813.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.54 : 1,991.60 = 813.96 : x
2. Step 2: Convert to fraction form
   1,443.54/1,991.60 = 813.96/x
3. Step 3: Cross multiply
   1,443.54x = 1,991.60 × 813.96
4. Step 4: Simplify right side
   1,443.54x = 1,621,083.65
5. Step 5: Solve for x
   x = 1,621,083.65/1,443.54
6. Step 6: Final answer
   x = 1,123.00