Question 3 (10 marks)a. A science instructor assigns a group of students to investigate the linear relationship between the pH of the water of a river and its water's hardness (measured in grains). One student wrote: "There was a very strong correlation of 1.35 between pH of the water and the water's hardness." Is the calculation of the correlation appropriate? Explain. (2 marks)b. A researcher found a very strong positive linear association (r = 0.987) between the percentage ofteens in a country that use marijuana and the percentage of teens who use other drugs. She concluded that the study shows that marijuana is a gateway drug; that is, marijuana use leads to the use of other drugs. Is her conclusion justified? (2 marks)c. If the outlier is removed from the data set, what will happen (increase, decrease, or remain the same) to the slope of the regression line and to the correlation (n) in the following? Explain. (6 marks)

i. ii. Outler