The builtin PlantGrowth data set contains three different groups, each representing a different plant food diet (you may need to type data(PlantGrowth) to activate it). The group labeled “ctrl” is the control group, while the other two groups are each a dif‑

ferent type of experimental treatment. Run the summary() command on PlantGrowth and explain the output. Create a histogram of the ctrl group. As a hint about R syntax, here is one way that you can access the ctrl group data:

PlantGrowth$weight[PlantGrowth$group==”ctrl”]

Also create histograms of the trt1 and trt2 groups. What can you say about the differ‑

ences in the groups by looking at the histograms?