Finding the Fourth Proportional to 1,443.08, 1,991.30 and 853.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.08 : 1,991.30 = 853.54 : x
2. Step 2: Convert to fraction form
   1,443.08/1,991.30 = 853.54/x
3. Step 3: Cross multiply
   1,443.08x = 1,991.30 × 853.54
4. Step 4: Simplify right side
   1,443.08x = 1,699,654.20
5. Step 5: Solve for x
   x = 1,699,654.20/1,443.08
6. Step 6: Final answer
   x = 1,177.80