To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens are buried in soil for a 2-year period. the maximum penetration (in mils) for each specimen is then measured, yielding a sample average penetration of x = 52.1 and a sample standard deviation of s = 4.7. the conduits were manufactured with the specification that true average penetration be at most 50 mils. they will be used unless it can be demonstrated conclusively that the specification has not been met. state the rejection region(s) for an ? = 0.05 test. if the critical region is one-sided, enter none for the unused region. round your answers to two decimal places?

In a study of the relationship between socio-economic class and unethical behavior, 129 university of california undergraduates at berkeley were asked to identify themselves as having low or high social-class by comparing themselves to others with the most (least) money, most (least) education, and most (least) respected jobs. they were also presented with a jar of individually wrapped candies and informed that the candies were for children in a nearby laboratory, but that they could take some if they wanted. after completing some unrelated tasks, participants reported the number of candies they had taken. it was found that those who were identiď¬ed as upper-class took more candy than others. in this study, identify: (a) the cases, (b) the variables and their types, (c) the main research question, (d) identify the population of interest and the sample in this study, and (e) comment on whether or not the results of the study can be generalized to the population, and if the ď¬ndings of the study can be used to establish causal relationships.