For the following questions you work with the built-in dataset CO2. It contains data on the CO2 uptake in two types of grassplants (Quebec and Mississippi), and this with two different treatments (chilled and not chilled):

 

   Plant   Type  Treatment conc uptake
1    Qn1 Quebec nonchilled   95   16.0
2    Qn1 Quebec nonchilled  175   30.4
3    Qn1 Quebec nonchilled  250   34.8
4    Qn1 Quebec nonchilled  350   37.2
5    Qn1 Quebec nonchilled  500   35.3
6    Qn1 Quebec nonchilled  675   39.2
7    Qn1 Quebec nonchilled 1000   39.7
8    Qn2 Quebec nonchilled   95   13.6
9    Qn2 Quebec nonchilled  175   27.3
10   Qn2 Quebec nonchilled  250   37.1

 

Question: Use ggplot2 graphics to create a plot where you can compare the chilled and nonchilled response for every type of plant. You can do this by plotting the density for both treatments in the same plot, and give them a different color. To see the graphs clearly, add a bit of transparency by using the alpha parameter. Store the graph in an object called p10.

 

Note: Because Dodona can check ggplot2 graphics directly, we do not need the ggplotify package and you can immediately start typing your graphical command(s).