In the context of this problem, explain why a one-sided ...

[shenderson6]

In the context of this problem, explain why a one-sided alternative hypothesis is more appropriate than a two-sided alternative.
 
  What will be an ideal response?

Question 2

Compare and contrast stratified sampling and cluster sampling. Under what circumstances would these techniques be chosen over a simple random sample?
 
  What will be an ideal response?

[poopface]

Answer to Question 1

A one-sided alternative is more appropriate since we are not interested in detecting possible low levels of impurity, only high levels of impurity.

Answer to Question 2

Stratified random sampling occurs when the population is divided into strata, and a random sample is drawn from each strata. Cluster sampling occurs when the population is divided geographically into clusters, and a census is performed on each chosen cluster. A researcher would typically choose one of these methods to ensure the representation of subsamples that may constitute small proportions of the sample.

[shenderson6]

Excellent

[atrochim]

Great answer, keep it coming