data visualization with r coursera week 1 quiz answers
Lesson 1: Data Visualization Tools and Packages
Practice Quiz
2. Which R statement creates a chart object based on the data frame “salesdata”, but allows you to vary the aesthetics from one layer to another?
- ggplot()
- qplot()
- ggplot(salesdata, aes(x = feature1, y = feature2))
- ggplot(salesdata)
3. True or False: The qplot() function has no defaults so you have more control over the output.
- True
- False
Graded Quiz
4. Which R packages will this course use to create data visualizations?
Select two answers.
- Leaflet
- None, you will use base R
- qplot
- ggplot2
5. Which chart is a type of part to the whole chart?
- Horizontal bar chart
- Stacked bar chart
- Grouped bar chart
- Bar chart
6. Which ggplot2 function can create a complete plot given the data, mappings, and geom as parameters?
- ggplot2()
- geom()
- qplot()
- ggplot()
Lesson 2: Create Basic Charts with ggplot2
Practice Quiz
8. Which of the following statements about histograms is true? Select two answers.
- A histogram displays quantitative data, while a bar chart displays qualitative data.
- A histogram displays qualitative data, while a bar chart displays quantitative data.
- A histogram counts the frequency of each individual number in the data set.
- A histogram divides data into bins and then counts the number of times a data point falls into each bin.
9. Complete the sentence: A pie chart is the same as a ___________________________ in polar coordinates.
- Grouped bar chart
- Stacked bar chart
- Horizontal bar chart
- Bar chart
Graded Quiz
10. Which parameter of the qplot() function changes the border color of the bars in a bar chart to blue?
- colour = I(“blue”)
- fill = I(“blue”)
- border = I(“blue”)
- outline = I(“blue”)
11. How can you improve the smoothness of a histogram?
- Always go with the default number of bins.
- Reduce the number of bins to increase the bin width.
- Increase the number of bins to reduce the bin width.
- Changing the number of bins has no impact of the smoothness of the histogram.
12. What step must you take before you can add the coord_polar() function to ggplot() to create a pie chart?
- Add the geom_bar(position = “stack”) command to the ggplot() function.
- Add the geom_bar(position = “dodge”) command to the ggplot() function.
- Set the x argument of the aes() function used in the ggplot() function to the factor.
- Add the geom_circle() command to the ggplot() function.
