Introduction to the App InsectSprays

• InsectSprays dataset is an R built-in data set. It measures the number of insects after being sprayed with 6 different insecticides.
• The InsectSprays App allows you to select any number of sprays, and make boxplots to demonstrate their effects.
• The App also allows you to select any 2 sprays, and carry out the t test to give the p-value. It can conclude whether these 2 selected sprays are significantly different.

IS.subset = subset(InsectSprays, InsectSprays$spray == c("B", "C", "D"))
library(ggplot2)
ggplot(IS.subset, aes(x = spray, y = count)) + geom_boxplot(aes(color = spray))

After t-test of spray B and spray C, the p value is

[1] 5.170528e-08

Conclusion: B and C are significantly different.