Over the last three weeks you have learned about the basics of simple and multiple linear regression. Today we will apply these skills to an actual data analysis. You are provided with a description of the data and a series of figures, tables, and linear regression model output. You are asked to summarize the results of these analyses using the handout below as your guide. Early studies by Tager et al. published between 1979 and 1983 attempted to systematically establish signs of reduced pulmonary function in children due to smoking cigarettes and second-hand smoke exposure. Today we will practice analyzing a subsample from the larger study designed to assess the relationship between a child being a current smoker and pulmonary function. The outcome variable of interest is forced expiratory volume (FEV), which is the amount of air an individual can exhale in the first second of a forceful breath; FEV is a measure of pulmonary functioning. The dataset includes 654 children with the following variables recorded: FEV (fev) measured in liters, age (age) measured in years, height (ht) measured in inches, sex (male) coded as 1=male, 0=female, and current smoker (smoker) coded as 1=current smoker, 0=non-smoker. DISCUSSION/NOTES: Q1. Using Output 1, prepare a table including some basic summaries of the quantitative (continuous or discrete) variables in the data set. Hint: please round to 2 digits as you might for a scientific report. Table 1A: General characteristics of the study population (quantitative variables) Summary (n=654) Mean + SD (Min, Max) Age (years) 9.93 + 2.95 (3, 19) Height (inches) FEV (liters)Output 1: Quantitative variable summaries # summary of the quantitative variable age summary (age) ## Min. 1st Qu. Median Mean 3rd Qu. Max. ## 3.000 8.000 10.000 9. 931 12.000 19.000 # standard deviation of the quantitative variable age sd(age) ## [1] 2.953935 # summary of the quantitative variable height summary (ht) ## Min. 1st Qu. Median Mean 3rd Qu. Max. ## 46.00 57.00 61.50 61. 14 65.50 74.00 # standard deviation of the quantitative variable height sd(ht) ## [1] 5. 703513 # summary of the quantitative variable FEV summary( fev) ## Min. 1st Qu. Median Mean 3rd Qu. Max. ## 0. 791 1.981 2.548 2. 637 3. 118 5.793 # standard deviation of the quantitative variable FEV sd(fev) ## [1] 0. 8670591