Heart Rate of Smokers A researcher wants to determine the effect that smoking has on resting heart rate. She randomly selects seven individuals from three categories: (1) nonsmokers, (2) light smokers (fewer than 10 cigarettes per day), and (3) heavy smokers (10 or more cigarettes per day) and obtains the following heart rate data (beats per minute):

(a) Test the null hypothesis that the mean resting heart rate for each category is the same at the  level of significance. Note: The requirements for a one-way ANOVA are satisfied.

(b) If the null hypothesis is rejected in part (a), use Tukey’s test to determine which pairwise means differ using a familywise error rate of .

(c) Draw boxplots of the three treatment levels to support the results obtained in parts (a) and (b).

The World Development Indicators database compiles data on household final consumption expenditure and on the number of fixed broadband Internet subscribers for virtually every country and region in the world. Shown here are data on household final consumption expenditure (in millions of constant 2,000 US$) and the number of fixed broadband subscribers (in thousands) for India for the most recent eight years of available data. Using these data, develop a regression model to predict total household final consumption expenditure by the number of fixed broadband Internet subscribers and by (number of fixed broadband Internet subscribers)² . Compare this model with a regression model to predict total household final consumption by only the number of fixed broadband Internet subscribers. Construct a scatter plot of the data. Does the shape of the plot suggest some alternative models in light of Tukey’s four-quadrant approach? If so, develop at least one other model and compare the model with the other two previously developed.