Finding the Fourth Proportional to 1,443.37, 1,991.84 and 853.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.37 : 1,991.84 = 853.89 : x
2. Step 2: Convert to fraction form
   1,443.37/1,991.84 = 853.89/x
3. Step 3: Cross multiply
   1,443.37x = 1,991.84 × 853.89
4. Step 4: Simplify right side
   1,443.37x = 1,700,812.26
5. Step 5: Solve for x
   x = 1,700,812.26/1,443.37
6. Step 6: Final answer
   x = 1,178.36