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.
Answer:
14 dimes and 4 quarters
Step-by-step explanation:
x= number of dimes
y=number of quarters
x-10=y
0.10x+0.25y=2.40
substitute for y
0.10x+0.25(x-10)=2.40
0.35x-2.50=2.40
0.35x=4.90
x=14
y=4
Answer:
k = 30, 
Step-by-step explanation:
Since 
is a solution, then it must satisfy the differential equation. So, we calculate the derivatives and replace the value in the equation. We have that
Then, replacing the derivatives in the equation we have:
Since 
is a positive function, we have that
.
Now, consider a general solution 
, then, by calculating the derivatives and replacing them in the equation, we get
We already know that r=5 is a solution of the equation, then we can divide the polynomial by the factor (r-5) to the get the other solution. If we do so, we get that (r-6)=0. So the other solution is r=6.
Therefore, the general solution is
