Statistics

3. When submitting their assignments, students were asked how many hours they spent working on the assignment. Below is a plot of their grade as a function of the number of hours they spent on the assignment. 100 Time (hrs) (a) Is the relationship roughly linear? (b) Are hours spent working on the assignment and assignment grade positively or negatively correlated? (0) Which of the two lines, A or B, is a better t to the data. Explain your reasoning. A simple linear regression model is tted and the equation of the best t line is found to be: Y = 24.3 + 13.4X (d) Write down the slope and intercept of the regression line? (e) Use the model tted above to predict the grade of a student who spent 3 hours working on the assignment. (f) The measures of variability for this data set are given as 811 = 51.5, SW = 12462.3 and Smy = 627.1. Compute and interpret the coeicient of determina- tion