english <- c(90,80,60,70)
english

math<-c(50,60,100,20)
math

df_midterm <- data.frame(english, math)
df_midterm

name <- c("song","ji","eun","ZZ6")

df_midterm <- data.frame(name, english, math)
df_midterm

science <- c(45,78,65,98)

df_midterm <-data.frame(name,math,english,science)
df_midterm

class <- c(1,1,2,2)
df_midterm <-data.frame(name,math,english,science, class)
df_midterm

mean(df_midterm$english)
mean(df_midterm$science)

max(df_midterm$science)
min(df_midterm$science)

df_midterm <- data.frame(english = c(90,80,60,70),
                         math=c(50,60,100,20),
                         class=c(1,1,2,2))
df_midterm

df_midterm2 <- data.frame(제품 = c("사과","딸기","수박"),
                            가격 = c(1800,1500,3000),
                            판매량 = c(24,38,13))
df_midterm2

mean(df_midterm2$가격)
mean(df_midterm2$판매량)

install.packages("readxl")
library(readxl)

df_exam <- read_excel("excel_exam.xlsx")
df_exam

mean(df_exam$science)
min(df_exam$math)
min(df_exam$science)
min(df_exam$english)
