Answer:
Option A.
Step-by-step explanation:
We know that we have:
220 students in grade 6.
170 students in grade 7.
100 students in grade 8.
Now we want to make a sample, to have the sample in the most representative way, so we should select the same percentage of students for each grade.
Let's analyze option A (this is the one that makes sense because has the larger number for 6th grade, then 7th grade and last for 8th grade)
Here we need to look at the quotient between the number of students selected for each grade, and the total number of students in the grade:
for 6th grade:
45/220 = 0.2
for 7th grade:
35/170 = 0.21
for 8th grade:
20/100 = 0.2
In the 3 cases we can see that we have almost the same ratio, which means that for the sample we selected around the 20% of each grade.
This is the most representative way of sampling in this case, then the correct option is A.
I believe that you need to divide 4 by 8 to get $0.50 per juice box.
Answer:
y(x) = 7e^(5x)
Step-by-step explanation:
The question says that the slope of the curve at every point P is five times the y-coordinate of P. This means that
dy/dx = 5y
Refer to solutions of differential equations, dy/dt = ky, being in the form of y(t) = y(0) e^(kt)
Using the above stated law now, we can relate to our equation, saying that
y(x) = y(0) e^(5x)
The point given from the question is, (0, 7). This also means that y(0) = 7. So finally, we can have
y(x) = 7e^(5x)
And that is our needed equation of the curve
