Consider the system of inequalities
1. Plot all lines that are determined by equalities (see attached diagram)
2. Determine which bounded part of the plane you should select:
means that you should take points with y-coordinates greater than or equal to 2 (top part of the coordinate plane that was formed by the red line);
means that you should take points with x-coordinates less than or equal to 6 (left part of the coordinate plane that was formed by the blue line);- for
you can check where the origin is placed. Since 
, the origin belongs to the needed part and you have to take the right part of the coordinate plane that was formed by green line. - for
you can check where the origin is placed. Since 
, the origin belongs to the needed part and you have to take the bottom part of the coordinate plane that was formed by orange line.
3. According to the previous explanations, the shaded region is as in A diagram.
Answer: correct choice is A.
Answer:
14x. ....................
1. You already did it.
2. Table
3. t (years since 1990)
4. n (# of cigarettes sold)
5. (t, n)
6. You can see the distribution of the data pretty neatly. There are also many more advantages including it's easier to calculate standard deviation, easier to see the mean, mode and median, and it's also much easier to just tell the extrema of the dataset by just looking at the scattergram.
