A biased example: Asking students who are in line to buy lunch
An unbiased example: Asking students who are leaving/going to lunch(<em>NOT buying </em><em>lunch</em><em />).
But in this case, the answer choices can be... confusing.
Don't panic! You're given numbers and, of course, your use of logic.
Answer choice A: 100 students grades 6-8
Answer choice B: 20-30 students any <em>one</em> grade<em></em><em>
</em>Answer choice C: 5 students
<em></em>Answer choice D: 50 students grade 8
An unbiased example would be to choose students from <em>any grade.</em> So we can eliminate choices B and D.
Now, the question wants to <em>estimate how many people at your middle school buy lunch.</em> This includes the whole entire school, and if you are going to be asking people, you aren't just going to assume that if 5 people out of 5 people you asked bought lunch, the whole school buys lunch.
So, to eliminate all bias and/or error by prediction, answer choice A, the most number of students, is your answer.
3+(1-2(3-5))
3+(1-6+10)
3+(1-16)
3+(-15)
-12
Answer:
are corresponding angles and are congruent to each other.
are alternate exterior angles and thus congruent to each other.
are interior angles on the same side, and they are supplementary(sum=180°).
Step-by-step explanation:
Given:
Line 
Line 
is traversal.
By angle properties we can name the angle relationship of given angle pairs.
are corresponding angles and are congruent to each other.
are alternate exterior angles and thus congruent to each other.
are interior angles on the same side, and thus they are supplementary.
We will call:
M=Mari
J=Jen
Initial equations:
M=2J
M+J=480
(the fact that they work 20 hours a week is not needed in this problem information)
Plug in:
2J+J=480
3J=480
J=160
Jen makes $160 a week.
Therefore:
M=2J
M=2(160)
M=320
Mari makes $320 per week
Jen makes $160 per week
Angle 4 is 77 degrees. Since angles 1, 2, and 3 must add up to 180 degrees, and angles 3 and 4 must also add up to 180 degrees, angles 1 + 2 must be equal to angle 4
