Finding the Fourth Proportional to 1,443.02, 1,991.41 and 813.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.02 : 1,991.41 = 813.57 : x
2. Step 2: Convert to fraction form
   1,443.02/1,991.41 = 813.57/x
3. Step 3: Cross multiply
   1,443.02x = 1,991.41 × 813.57
4. Step 4: Simplify right side
   1,443.02x = 1,620,151.43
5. Step 5: Solve for x
   x = 1,620,151.43/1,443.02
6. Step 6: Final answer
   x = 1,122.75