Lesson 7 editorial issues

[dickens-ladco]

• Revise as noted: "We use linear regression to explore the relationships between two variables. In particular, in studying air quality, we frequently use linear regression to figure out what the relationship is between [certain] different meteorological parameters [commonly measured] (e.g. temperature, solar radiation, humidity, wind, etc) and chemicals of interest (e.g. ozone)."
• After "xlab = expression("Temperature (" degree "F)"), ", add: "#this script will print the degree symbol"
• Below the output for summary(ozone_temp_lm), pull out some of the key information about the line, such as the slope, intercept, and R2. Some of these are obvious (intercept and R2) but the slope is sort of disguised.
• Add bolded text: "We can now add the regression line from our model to our original scatterplot using the abline() function"
• Please include an example of how to add information to a text box on the figure (with abline()) rather than just saying you can do it - I don't think they know how to do this yet.
• Add the bolded text: "Additionally, if you plot the linear model output (which we saved as the variable ozone_temp_lm), you get four plots of interest that can help you evaluate the goodness-of-fit of your regression line. " (or something like this)