Finding the Fourth Proportional to 1,443.34, 1,991.82 and 853.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.34 : 1,991.82 = 853.90 : x
2. Step 2: Convert to fraction form
   1,443.34/1,991.82 = 853.90/x
3. Step 3: Cross multiply
   1,443.34x = 1,991.82 × 853.90
4. Step 4: Simplify right side
   1,443.34x = 1,700,815.10
5. Step 5: Solve for x
   x = 1,700,815.10/1,443.34
6. Step 6: Final answer
   x = 1,178.39