GR 1 Review

Identify one variable that is categorical and one variable that is quantitative (numerical).

For the scatterplot pictured, describe the relationship.

• There is no linear relationship.

• There appears to be a positive, linear relationship.

• The linear relationship appears to be the graph of a quadratic function.

• There appears to be a negative relationship.

This plot contains a lot of points that are clustered in the same areas. How would you refine this plot by adding some transparency to the points?

When is it most appropriate to use geom_jitter() over changing the transparency of the points?

• When there are a large number of data points overlapping, making it hard to discern individual points

• When you want to emphasize the specific values of data points without introducing any randomness

• You shouldn't use geom_jitter() and should just change the color of the points.

Which best describes what the shown code chunk is doing?

• Each city's average sales for year 2009 sorted from highest to lowest

• Each city's average sales sorted from highest to lowest

• Each city's total sales for year 2009 sorted from lowest to highest

• Each city's total sales for year 2009 sorted from highest to lowest

Which of the following code chunks adds a column to the dataset that displays the percent of the listings sold for that month. This is found by dividing the number of sales by the number of listings and then multiplying by 100.

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How would you change the shown code chuck to show which city had the highest sales in May 2009?

Which type of plot is most appropriate for viewing how number of sales compares for 2 cities?

• Side-by-side boxplot

• Linegraph

• Scatterplot

• Histogram

Faceted histograms allow us to visualize the distribution of a single numerical variable across the values of a categorical variable.

• True

• False

If a dataset is considered to be "tidy," what does the number of columns represent?

• Number of observations

• Number of variables