Finding the Fourth Proportional to 1,443.43, 1,991.91 and 813.97

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.43 : 1,991.91 = 813.97 : x
2. Step 2: Convert to fraction form
   1,443.43/1,991.91 = 813.97/x
3. Step 3: Cross multiply
   1,443.43x = 1,991.91 × 813.97
4. Step 4: Simplify right side
   1,443.43x = 1,621,354.98
5. Step 5: Solve for x
   x = 1,621,354.98/1,443.43
6. Step 6: Final answer
   x = 1,123.27