The first sampling method is Convenient Sampling. It is biased sampling and it is not representative of a random sample.
The second sampling method is Systematic Sampling. If this method of sampling is drawn from the population, it is an efficiently randomized sampling method.
Let us review the given answers.
1. Both samples should be exactly the same.
INCORRECT
2. Neither sample will be representative.
Because the second sampling method can be random, this answer is
INCORRECT.
3. The first sampling method, ..., is the most representative,
INCORRECT
4. The second sampling method, ..., is the most representative.
CORRECT
Answer: $2.26
10% of $52.50 is 5.25. Then, $52.50-$5.25 is $47.25. $49.99-$47.25 is $2.26
Answer:
all her patients patients with no cavities
patients younger than 18
every patient with braces
Step-by-step explanation:
when a sample is selected in a manner that some elements, in this case patients, of population have higher or lower probability of sampling then that sample is biased.
From given case, all the following are biased samples
all her patients patients with no cavities
patients younger than 18
every patient with braces
because they are non-random sample of a population in which all other elements were not equally likely to be chosen!
Answer:
The number of ways is equal to 
Step-by-step explanation:
The multiplication principle states that If a first experiment can happen in n1 ways, then a second experiment can happen in n2 ways ... and finally a i-experiment can happen in ni ways therefore the total ways in which the whole experiment can occur are
n1 x n2 x ... x ni
Also, given n-elements in which we want to put them in a row, the total ways to do this are n! that is n-factorial.
For example : We want to put 4 different objects in a row.
The total ways to do this are 
ways.
Using the multiplication principle and the n-factorial number :
The number of ways to put all 40 in a row for a picture, with all 12 sophomores on the left,all 8 juniors in the middle, and all 20 seniors on the right are : The total ways to put all 12 sophomores in a row multiply by the ways to put the 8 juniors in a row and finally multiply by the total ways to put all 20 senior in a row ⇒
