Amanufacturer of light bulbs advertises that, on average, its long-life bulb will last more than 4800 hours. to test this claim, a statistician took a random sample of 96 bulbs and measured the amount of time until each bulb burned out. the mean lifetime of the sample of bulbs is 4825 hours and has a standard deviation of 320 hours. can we conclude with 90% confidence that the claim is true?

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.