To determine customer opinion of their pricing, greyhound lines randomly selects 90 busses during a certain week and surveys all passengers on the busses. what type of sampling is used?

Cluster sampling.

Step-by-step explanation:

Cluster sampling is a sampling technique in statistics in which the  researcher splits the entire population into different groups called clusters.After that he randomly select a sample from the clusters from the population and survey all elements of sampled clusters.Researcher performs his analysis on data from the sampled clusters.

In the given situation Greyhound Lines randomly selects 90 buses during a certain week and surveys all passengers on the buses.

Here, week= Cluster

Buses = Elements

Therefore , the type of sampling is used = Cluster sampling.

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )