Write an R script that contains statements to address the following numbered ite

Question

Write an R script that contains statements to address the following numbered items.

The function call, rnorm(1), generates a normal random number. Use replicate() to generate 10 normal random numbers and assign them to a vector called nums.

The R statement, data(iris), loads the built-in R data set iris. This dataset has 150 rows and 5 columns. The 5 column names are
"Sepal.Length","Sepal.Width","Petal.Length","Petal.Width" and "Species".

Write R code(s) to return a list of 4 items that correspond to the averages of the first 4 columns in iris. The contents of the list should be as follows:

$Sepal.Length
[1] 5.843333

$Sepal.Width
[1] 3.057333

$Petal.Length
[1] 3.758

$Petal.Width
[1] 1.199333

With the iris dataset still loaded,write R code(s) to return a vector of 4 items that correspond to the averages of the first 4 columns in iris. The contents of the vector should be as follows:

Sepal.Length

Sepal.Width

Petal.Length

Petal.Width

5.843333

3.057333

3.7580000

1.199333

The following R code converts the contents of the first 4 columns in iris to a matrix called data.
data=as.matrix(iris[,1:4])Write R code(s) to use apply() to return a vector that contains the max values of the 4 columns. The contents of the vector should be as follows [Hint, use max()]:

Sepal.Length

Sepal.Width

Petal.Length

Petal.Width

7.9

4.4

6.9

2.5

Sepal.Length

Sepal.Width

Petal.Length

Petal.Width

5.843333

3.057333

3.7580000

1.199333

Explanation / Answer

library(datasets)
data(iris)
iris
?iris
names(iris)

f <- factor(iris$Species)
class(f)
f

#ordered(s)

1. what R code returns a vector of the means of the variables 'Sepal.Length', 'Sepal.Width', 'Petal.Length', and 'Petal.Width'?

colMeans(iris)
apply(iris[, 1:4], 1, mean)
rowMeans(iris[, 1:4])
apply(iris[, 1:4], 2, mean)

#Ans: apply(iris[, 1:4], 2, mean)
#Sepal.Length Sepal.Width Petal.Length Petal.Width
#    5.843333     3.057333     3.758000     1.199333

2.
apply(iris[,1:4],2,max

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