Answer
a) y | p(y)
25 | 0.8
100 | 0.15
300 | 0.05
E(y) = ∑ y . p(y)
E(y) = 25 × 0.8 + 100 × 0.15 + 300 × 0.05
E(y) = 50
average class size equal to E(y) = 50
b) y | p(y)
25 |
100 |
300 |
E(y) = ∑ y . p(y)
E(y) = 25 × 0.4 + 100 × 0.3 + 300 × 0.3
E(y) = 130
average class size equal to E(y) = 130
c) Average Student in the class in a school = 50
Average student at the school has student = 130
Answer:
2x -y ≥ 4
Step-by-step explanation:
The intercepts of the boundary line are given, so it is convenient to start with the equation of that line in intercept form:
... x/(x-intercept) + y/(y-intercept) = 1
... x/2 + y/(-4) = 1
Multiplying by 4 gives the equation of the line.
... 2x -y = 4
This line divides the plane into two half-planes. The half-plane that is shaded is the one for larger values of x and/or smaller values of y than the ones on the line. So, for some given y, if we increase x we will get a number from our equation above that is greater than 4. Hence, the inequality we want is ...
... 2x -y ≥ 4
We use the ≥ symbol because the line is solid, so part of the solution space.
