Finding the Fourth Proportional to 1,442.39, 1,989.43 and 994.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,442.39 : 1,989.43 = 994.40 : x
2. Step 2: Convert to fraction form
   1,442.39/1,989.43 = 994.40/x
3. Step 3: Cross multiply
   1,442.39x = 1,989.43 × 994.40
4. Step 4: Simplify right side
   1,442.39x = 1,978,284.22
5. Step 5: Solve for x
   x = 1,978,284.22/1,442.39
6. Step 6: Final answer
   x = 1,371.54