Question: (8 marks). The data file data2_Q5.sav contains information on the percentage of people who brush their teeth at least once a day and the percentage of people who have caries for a range of developed and developing countries.

a. Produce a scatter plot of teeth-brush rate against percentage of caries and comment on the results. (2 marks)

b. Calculate Pearson’s correlation coefficient for these data. Test whether the correlation coefficient is significantly different from zero. (2 marks)

c. Calculate Spearman’s rank correlation coefficient for these data. Test whether the correlation coefficient is significantly different from zero. (2 marks)

d. Which of the two correlation coefficients do you think is a more appropriate summary of the relationship between the variables and why? (2 marks)