library(openxlsx)
sample1<-read.xlsx("http://kanggc.iptime.org/book/data/stat-1.xlsx") 
mid<-sample1$mid
final<-sample1$final
total<-sample1$total
grade<-sample1$grade
summary(sample1)

par(mfrow=c(1,3))
boxplot(mid, main="Box plot of mid")
boxplot(final, main="Box plot of final")
boxplot(total, main="Box plot of total")

par(mfrow=c(1,1))
table(grade)
slices<-c(4,11,11,16,9,5,3,1)
lbls<-c("1µî±Þ","2µî±Þ","3µî±Þ","4µî±Þ","5µî±Þ","6µî±Þ","7µî±Þ","8µî±Þ")
pie(slices, labels=lbls, main="Pie Chart of Total Score")

counts<-table(total, grade)
barplot(counts, main="Bar Chart of Total Score", xlab="Grade")