Finding the Fourth Proportional to 1,443.47, 1,991.77 and 813.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.47 : 1,991.77 = 813.88 : x
2. Step 2: Convert to fraction form
   1,443.47/1,991.77 = 813.88/x
3. Step 3: Cross multiply
   1,443.47x = 1,991.77 × 813.88
4. Step 4: Simplify right side
   1,443.47x = 1,621,061.77
5. Step 5: Solve for x
   x = 1,621,061.77/1,443.47
6. Step 6: Final answer
   x = 1,123.03