PFA

PFA


(2) A college bookshop should order books two months prior to the commencement of each semester. They assume that the number of books that will eventually be sold for any particular course is related to the number of students registered for the course when the books are ordered. They would like to build a linear regression model which can be used to identify how many books to order. From past records of the bookstore, the number of students registered and the number of books sold for a course for 12 different semesters were obtained and given below: Semester Students Books 1 36 31 2 28 29 3 35 34 4 39 35 5 30 29 6 30 30 7 31 30 8 38 38 9 36 34 10 38 33 11 29 29 12 26 26 (a). Draw a scatter plot for the above data and discuss whether the relationship between the number of students registered and the books ordered is linear? (b). Compute the correlation coefficient and interpret. (c). Obtain the regression equation to predict the number of books should order for the coming semesters. (d). Calculate the standard error for each observation. (e). Draw a suitable residual plot and comment on the adequacy of the model.