HELP

Problem 5 (8 points) Eight randomly selected people were asked to watch a 1-hour documentary. In the middle of the film, a commercial advertising a breakfast cereal appeared. Each person was shown a commercial of a different length ranging from 20 to 48 seconds, with the essential content being the same in all cases. After the documentary, each person was given a test to determine how much he or she remembered about the product. Unfortunately, some data has been lost. The remaining data about the commercial times and test scores (on a 20-point scale) is given below: Person 1 3 4 5 6 7 8 x: Length of commercial 20 24 28 32 36 40 44 48 y: Test score 10 8 11 . . . 16 . . . 13 Before some of the data was lost, we were able to compute the following summary statistics: Elli = 272, 21- yi = 95, Li Liyi = 3320, Ex? = 9920, and >_ y? = 1150. (a) (3 points) Calculate the correlation coefficient of the data. What percentage of the total variation in test scores would be explained by a regression line? (b) (3 points) Use the simple regression line y = a + br to predict the missing test scores for the given commercial lengths. (c) (2 points) Is it possible to compute the Residual Sum of Squares