Finding the Fourth Proportional to 1,442.17, 1,990.61 and 853.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,442.17 : 1,990.61 = 853.12 : x
2. Step 2: Convert to fraction form
   1,442.17/1,990.61 = 853.12/x
3. Step 3: Cross multiply
   1,442.17x = 1,990.61 × 853.12
4. Step 4: Simplify right side
   1,442.17x = 1,698,229.20
5. Step 5: Solve for x
   x = 1,698,229.20/1,442.17
6. Step 6: Final answer
   x = 1,177.55