Finding the Fourth Proportional to 3,919.72, 5,879.76 and 998.05

Step by Step Solution

1. Step 1: Write the proportion equation
   3,919.72 : 5,879.76 = 998.05 : x
2. Step 2: Convert to fraction form
   3,919.72/5,879.76 = 998.05/x
3. Step 3: Cross multiply
   3,919.72x = 5,879.76 × 998.05
4. Step 4: Simplify right side
   3,919.72x = 5,868,294.47
5. Step 5: Solve for x
   x = 5,868,294.47/3,919.72
6. Step 6: Final answer
   x = 1,497.12