Many high school students take either the sat or the act. however, some students take both. data were collected from 60 students who took both college entrance exams. the average sat score was 912 with a standard deviation of 180. the average act score was 21 with a standard deviation of 5. the correlation between the two variables equals 0.817.

what fraction of the variation in the values of the sat scores is accounted for by the linear relationship between the sat and act scores?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.