For questions 1-3, select the choice that best answers the question. (2 points each)
1. Which of the following studies would a scatterplot not be appropriate way to show sample data?
a) Is there an association between vehicle weight (in pounds) and gas efficiency (miles per gallon)?
b) Is there an association between the color ink a student uses on a final exam and their grade?
c) Is there a relationship between the cost of Lego © set and the number of pieces in the set?
d) Is there an association between the age of a driver and the number of speeding tickets he/she has received?
2. Which of the following values of the correlation coefficient most likely corresponds to the scatter plot below?
a) r = -0.895
b) r = 1
c) r = 0.01
d) r = 0.895
3. Which of the following statements about or examples of a correlation coefficient is valid?
a) Because the correlation coefficient between test time and score is -0.56, the correlation coefficient between test score and time must be 0.56 (the positive value).
b) There is a strong positive correlation between a person's yard size and whether or not they own a dog.
c) For a sample of 50 students, the correlation coefficient between weight (kg) and height (in) was found to be 0.78kg/in
d) A correlation coefficient of r = 0.84 denotes just as strong a relationship as a correlation coefficient of r = -0.84.