set.seed(202003)
x <- rnorm(10, mean = 2, sd = 3)
x
mean(x)
y <- rnorm(10, mean = 2, sd = 3)
y
x
cov(x,y)
cor(x,y)
cor(x,-y)
rgamma(10, 1, 3)
rt(10, 20)
rt(10, 100)

macierz <- matrix(0, nrow = 10, ncol = 5)
macierz[,1] <- x
macierz[,2] <- y

set.seed(202003)
macierz[,3] <- rgamma(10, 1, 3)

set.seed(202003)
macierz[,4] <- rt(10, 20)

set.seed(202003)
macierz[,5] <- rt(10, 100)
macierz

cov(macierz)

cor(macierz)

t.test(macierz[,1], alternative = "two.side", mu = 2)

t.test(macierz[,1], alternative = "two.side", mu = 4.73)

t.test(macierz[,1], macierz[,2])

shapiro.test(macierz[,1])
shapiro.test(macierz[,5])
?t.test
macierz[,1]