Finding the Fourth Proportional to 1,017.98, 1,519.28 and 919.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,017.98 : 1,519.28 = 919.57 : x
2. Step 2: Convert to fraction form
   1,017.98/1,519.28 = 919.57/x
3. Step 3: Cross multiply
   1,017.98x = 1,519.28 × 919.57
4. Step 4: Simplify right side
   1,017.98x = 1,397,078.39
5. Step 5: Solve for x
   x = 1,397,078.39/1,017.98
6. Step 6: Final answer
   x = 1,372.40