A local police precinct has seen a recent enhance in the number of complaints filed regarding how officers are interacting with the public. Before addressing the issue, the commander needs to know if the issue is wide spread all through the precinct or if it is isolated to the specific complainants. To explain this, the commander has the community relations unit randomly call houses all through the precinct and ask how fairly they feel the police treats the public. The commander then compares the information gathered by the random sample to the called parameters for the entire city to explain if his precinct's score is significantly lower than average.

a)  Would the commander conduct a 1-tailed or 2-tailed hypothesis test? Describe why.

b)  Use the information below to conduct a z-test using p=.01 as your alpha level. Make sure you complete all 5 steps and show your work/answers for every step.

Sample                        Population

Mean = 2.64               Mean = 2.72

SD = 0.56                    SD = 0.31

n = 86

c)  Measure a 99% confidence interval for the above sample.