Finding the Fourth Proportional to 1,442.38, 1,990.53 and 853.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,442.38 : 1,990.53 = 853.30 : x
2. Step 2: Convert to fraction form
   1,442.38/1,990.53 = 853.30/x
3. Step 3: Cross multiply
   1,442.38x = 1,990.53 × 853.30
4. Step 4: Simplify right side
   1,442.38x = 1,698,519.25
5. Step 5: Solve for x
   x = 1,698,519.25/1,442.38
6. Step 6: Final answer
   x = 1,177.58