Finding the Fourth Proportional to 1,439.89, 1,987.53 and 998.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.89 : 1,987.53 = 998.37 : x
2. Step 2: Convert to fraction form
   1,439.89/1,987.53 = 998.37/x
3. Step 3: Cross multiply
   1,439.89x = 1,987.53 × 998.37
4. Step 4: Simplify right side
   1,439.89x = 1,984,290.33
5. Step 5: Solve for x
   x = 1,984,290.33/1,439.89
6. Step 6: Final answer
   x = 1,378.08