Finding the Fourth Proportional to 1,443.39, 1,991.71 and 813.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.39 : 1,991.71 = 813.87 : x
2. Step 2: Convert to fraction form
   1,443.39/1,991.71 = 813.87/x
3. Step 3: Cross multiply
   1,443.39x = 1,991.71 × 813.87
4. Step 4: Simplify right side
   1,443.39x = 1,620,993.02
5. Step 5: Solve for x
   x = 1,620,993.02/1,443.39
6. Step 6: Final answer
   x = 1,123.05