Consider the following document-term table containing raw term frequencies. Answer the following questions, and in each case give the formulas you used to perform the necessary computations. a. Compute the new weights for all the terms in document DOC4 using the tf x idf approach. b. Compute the new weights for all the terms in documents DOC4 using the signal-to-noise ratio approach. c. Using the Keyword Discrimination approach, determine if Term4 is a good index term or not (by computing it's discriminant). To compute average similarities use Cosine similarities use Cosine similarity as your similarity measure. Show your work