MODULE 6 TEST- STATISTICS questions and answers with solutions 2025

Based on the results shown, what do you think the relationship is between age and depression? a) It is positively correlated b) It is negatively correlated c) No correlation d) Can't tell from this display - ANSWER The correct answer is d. We can not determine the relationship between age and depression as we don't know how the data pair up. The other question answer choices cannot be determined because to assess correlation we need to be able to see how the data is paired. A car company wanted to study the relationship between the weight of the car and the car's average gas mileage, so they collected data from several of their cars and wrote down their weights and average gas mileage and plotted this data on the scatterplot below. The least squares regression line for the data is y=−0.0084x+48.8 , where x is the weight of the car in pounds and y is the average gas mileage (in miles per gallon). What is the predicted gas mileage for a car that weighs 2500 pounds? a) 29.18 miles per gallon b) 26.4 miles per gallon c) 27.8 miles per gallon d) 69.8 miles per gallon - ANSWER The correct answer is c. To find the predicted gas mileage for a car that weighs 2500 pounds, substitute x=2500 into the regression equation and solve for y . y=−0.0084(2500)+48.8 , so y=27.8 . Which of the following can help prevent Simpson's Paradox from occurring? a) Having the greatest number of subjects in the lowest performing trial. b) Having an equal number of subjects exposed to each of the treatments in each trial. c) Having the greatest number of subjects in the highest performing trial. d) Having each subject be exposed to each treatment in the trial. - ANSWER The correct answer is b. Simpson's paradox is avoided by having an equal number of subjects exposed to each of the treatments in each trial. Due to budget cuts, a scientist had her funding reduced for a research project. Her support only enabled her to collect 2 data points, (2,3.26) and (4,6.52) . The data points are plotted below. What is your estimate of the correlation coefficient? a) −1 b) Zero c) 1 d) Cannot be determined - ANSWER The correct answer is c. Th