Finding the Fourth Proportional to 1,443.30, 1,991.82 and 853.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.30 : 1,991.82 = 853.75 : x
2. Step 2: Convert to fraction form
   1,443.30/1,991.82 = 853.75/x
3. Step 3: Cross multiply
   1,443.30x = 1,991.82 × 853.75
4. Step 4: Simplify right side
   1,443.30x = 1,700,516.33
5. Step 5: Solve for x
   x = 1,700,516.33/1,443.30
6. Step 6: Final answer
   x = 1,178.21