Finding the Fourth Proportional to 1,391.94, 1,919.61 and 998.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.94 : 1,919.61 = 998.82 : x
2. Step 2: Convert to fraction form
   1,391.94/1,919.61 = 998.82/x
3. Step 3: Cross multiply
   1,391.94x = 1,919.61 × 998.82
4. Step 4: Simplify right side
   1,391.94x = 1,917,344.86
5. Step 5: Solve for x
   x = 1,917,344.86/1,391.94
6. Step 6: Final answer
   x = 1,377.46