Tammy's sample may not be considered valid because, on the first hand, it is said that she only asked students from her " Math Class".
If she wants to have a survey to find out the favorite subject of the students at her school, she must conduct a survey involving all the students in her school, not just in her class. What she did is just subjective. She should use a tally listing the different subjects and compare the number of students per subject. This way, she can have an objective representation of the least liked subjects and the most liked subjects of the students on her school.
Illustrating her survey through statistics may be more reliable and valid because it shows frequencies in which she can calculate easily and accurately the percentage of the number of students per subject, in a more objective manner.
Answer:
$6 = cost of small box
$8 = cost of large box
Step-by-step explanation:
Let s = cost of small box
l = cost of large box
(1) 12s + 3l = 96 (2) 6s + 6l = 84
Multiply by -2 <u> -24s - 6l = -192</u>
-18s = - 108
s = $6 = cost of small box
12(6) + 3l = 96
72 + 3l = 96
3l = 24
l = $8 = cost of large box
Eliminate y's
multiply second equaiton by 4
4x+4y=-4
add to first equation
3x-4y=-24
<u>4x+4y=-4 +</u>
7x+0y=-28
7x=-28
divide both sides by 7
x=-4
sub back
x+y=-1
-4+y=-1
add 4 to both sides
y=3
(x,y)
(-4,3)
D is answer
Had to look for the options and here is my answer.
Starting from the 1950s, both robberies and air pollution has increased and the conclusion that we can say regarding this increase is NOT JUSTIFIABLE. It is not justifiable because population is a different variable and they are not directly related to each other. Hope this helps.
