8. The mean running time of a certain variety of nickel-cadmium rechargeable flashlight battery is known to be normally distributed with a mean of 8.5. A change in production method for this
battery has been proposed, and a simple random sample of 64 batteries produced by the new
method has mean running time of 8.72 hours. Assume the population is normally distributed with
a standard deviation of 0.55 hour as known and remains unchanged, test a claim that the new
production method improving the battery mean running time using 0.05 significance level.

What is the factored form of x2 − 4x − 5? (x + 5)(x − 1) (x + 5)(x + 1) (x − 5)(x − 1) (x − 5)(x + 1)

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.

Iwill arward ! , i if bt ≅ eu , bu ≅ et , prove: ∠b ≅ ∠e. fill in the blanks: draw segment ut ≅ bt≅ bu ≅ △ubt ≅ △