Finding the Fourth Proportional to 1,443.13, 1,991.41 and 813.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.13 : 1,991.41 = 813.76 : x
2. Step 2: Convert to fraction form
   1,443.13/1,991.41 = 813.76/x
3. Step 3: Cross multiply
   1,443.13x = 1,991.41 × 813.76
4. Step 4: Simplify right side
   1,443.13x = 1,620,529.80
5. Step 5: Solve for x
   x = 1,620,529.80/1,443.13
6. Step 6: Final answer
   x = 1,122.93