Answer:
Cluster sample
Step-by-step explanation:
This is an example of a cluster sample. In a cluster sample, the examiner divides the population into groups (each one of these groups is called a cluster) and once the examiner has these clusters, takes one of them and recollects the data from ALL the members of that cluster. In this case, the teacher divided the class in 3 different groups and then selects one of these groups and asks the average amount of time per week he/she spent studying.
Answer:
y = -1/4x^2 - x + 3
Step-by-step explanation:
(-6,0)
(-4,3)
(2,0)
36a - 6b + c = 0
16a -4b + c = 3
4a + 2b + c = 0
c = -4a - 2b
36a - 6b - 4a -2b = 0
16a - 4b -4a - 2b = 3
32a -8b = 0
12a - 6b = 3
4a - b = 0
4a - 2b = 1
b = -1
4a + 1 = 0
4a = -1
a = -1/4
c = 1 + 2 = 3
y = -1/4x^2 - x + 3
x^2 + 6x + 7 = (x + 3)^2 - 2
So the axis of symmetry is x = -3
It mean that everything is goin down and that there isnt anything interfering with it
6.43 rounded to the nearest tenth is 6.40
The place after the decimal is the tenths place. We rely on the value of the hundredths place to know whether we round it up or we round it down to the nearest tenths. If the number is 5 and above, we round it up. If the number is below 5, we round it down.
3 is below 5 therefore from 6.43 we round it down to 6.40
