Finding the Fourth Proportional to 1,441.31, 1,989.92 and 999.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,441.31 : 1,989.92 = 999.05 : x
2. Step 2: Convert to fraction form
   1,441.31/1,989.92 = 999.05/x
3. Step 3: Cross multiply
   1,441.31x = 1,989.92 × 999.05
4. Step 4: Simplify right side
   1,441.31x = 1,988,024.58
5. Step 5: Solve for x
   x = 1,988,024.58/1,441.31
6. Step 6: Final answer
   x = 1,379.32