Statistics Chapter 9-10 Questions & Answers

Statistics Chapter 9-10 Questions & Answers A gambler conducts a study to determine whether the time it took a horse to run its last race can be used to predict the time it takes the horse to run its next race. In this study, the explanatory variable is - ANSWER: the time it took a horse to run its last race A regression analysis between weight (y in pounds) and height (x in inches) resulted in the following least squares line: y^=120+5x. This implies that if the height is increased by 1 inch, the weight is expected to: - ANSWER: increase by 5 pounds A researcher observes that, on average, the number of divorces in cities with major league baseball teams is larger than in cities without major league baseball teams. The most plausible explanation for this observed association is - ANSWER: the association is due to the presence of a lurking variable (major league teams tend to be in large cities with more people, hence a greater number of divorces) A study found a correlation of r = -0.61 between the gender of a worker and his or her income. You may correctly conclude - ANSWER: this is incorrect because r makes no sense here Can one predict a student's score on the midterm exam in a statistics course from the number of hours the student spent studying for the exam? To explore this, the teacher of the course asks students how many hours they spent studying for the exam and then makes a scatterplot of the time students spent studying and their scores on the exam. In making the scatterplot, the teacher should - ANSWER: plot time spent studying for the exam on the horizontal axis Consider the linear equation y=b0+b1x a) In the equation, b0 is b) In the equation, b1 is