Answer:
a) Convenient
b) Cluster
c) Stratified
d) Systematic
e) Random
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
Situation a:
Asks all from a single group(sitting passengers), that is, convenint sample.
Situation b:
First she separates the students by row, then from each row, she chooses all students. So this is Cluster sampling.
Situation c:
The manager separates the stores by location, and then in each location, random customers are chosen. This is an example of Stratified sampling.
Situation d:
Marks for every fourth patron, that is, every 4th element. So Systematic sampling.
Situation e:
People chosen at random, so Random sampling.
tells us that: When we add 5 to a variable x, we get 20. As it has a unique value for x and is completely equal to it(i.e. 15), It is an equality.
tells us that: A variable x equals to 5. Hence, as x is unique for 5 and is wholly equal to it, it's an equality too.
tells us that: A variable x isn't 5 but lesser than it. As we cannot equate it to 5, nor we are given the nature of the variable x, it is an Inequality.
is an expression; It can't be called an equation or an inequality unless we relate it with another expression.