17. Data from 100 male students was collected. Which variable is most likely to follow a Normal model? a. hours of assigned homework last week b. head circumference c. number of TV sets at home d. eye color 18. Which of the following scatterplots has a correlation of r= -0.51? a. b. C. d. 19. What would a correlation coefficient of 0 between two quantitative variables indicate? a. We have done something wrong in our calculation of r. b. There is no association between the two variables. c. There is no linear association between the two variables. d. None of the above. 20. Identify what is wrong with the following statement, "The correlation between Olympic gold medal times for the 100 m dash and year is -1.37. a. Correlation has units. b. Both variables must be quantitative. c. The association between the variables must be linear. d. Correlation is always between -1 and +1