R quiz

Which of the following is a valid way to create a numeric vector in R?

• c(1, 2, 3)

• c[1,2,3]

• vector[1, 2, 3]

• vector(1,2,3)

What is the data type of the result of the following expression?

typeof(3L)

• "double"

• "integer"

• "numeric"

• "logical"

What will be the output of this code?

x <- c(TRUE, FALSE, TRUE)

sum(x)

• 3

• 2

• 1

• Error

Which function is used to check the structure of an R object?

• summary()

• structure()

• class()

• str()

Write R code to assign the value 5 to a variable named

(a)  

Which function is used to create a bar plot in R?

• plot.bar()

• barplot()

• barchart()

• bar()

What is the output of mean(c(2, 4, 6, NA), na.rm = TRUE)?

• 4

• NA

• 3

• Error

Which function is used to read CSV files into R?

• read.csv()

• read.txt()

• import.csv()

• open.csv()

Which package is commonly used for advanced data visualization in R?

• dplyr

• tidyverse

• ggplot2

• lubridate

How can you view the first few rows of a data frame in object 'df' in R?

• view(df)

• first(df)

• head(df)

• df[1:6,]