Let x1, x2, and x3 represent the times necessary to perform three successive repair tasks at a certain service facility. suppose they are independent, normal rv's with expected values μ1, μ2, and μ3 and variances σ12, σ22, and σ32, respectively. if μ1=μ2 = μ3=70 and σ1^2=σ2^2=σ3^2=21, calculate p(to < 231) and p(168 < t< 231).

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.

A. 2.3y +2 +3.1y = 4.3y + 1.6 + 1.1y + 0.4 b. + 25 - = c. 5/8x + 2.5 = 3/8x + 1.5 + 1/4x d. 1/3 + 1/7y = 3/7y

5of the first 50 shoppers at a grocery store buy apples. how many shoppers can the store manager expect to check out before 25 customers buy applesa.) 100b.)150c.)200d.)250