Finding the Fourth Proportional to 3,920.15, 5,880.20 and 998.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920.15 : 5,880.20 = 998.42 : x
2. Step 2: Convert to fraction form
   3,920.15/5,880.20 = 998.42/x
3. Step 3: Cross multiply
   3,920.15x = 5,880.20 × 998.42
4. Step 4: Simplify right side
   3,920.15x = 5,870,874.89
5. Step 5: Solve for x
   x = 5,870,874.89/3,920.15
6. Step 6: Final answer
   x = 1,497.61