Q1. Consider the following ratings matrix with three users and six items. Ratings are on a 1-5 star scale. Compute the following from data of this matrix: (20 points) Item 1 Item 3 Item 6 User 1 User 2 User 3 Item 2 5 3 Item 4 5 3 3 Item 5 1 1 4 2 4 2 1 Table 1: Data of ratings from three users for six items. a) Treat missing values as 0. Compute the jaccard similarity between each pair of users. b) Treat missing values as 0. Compute the cosine similarity between each pair of users. c) Normalize the matrix by subtracting from each non-zero rating, the average value for its user. Show the normalized matrix. d) Compute the centered) cosine similarity between each pair of users using the above nor- malized matrix