QUIZ-1

1. Select all tools required for building a data science project*

• Transform

• Visualize

• statistics

• tidy

• analysis

2. CRAN is a*

• R Community

• a central software repository

• a library

• R package

3. define the class of vector  X<-c(1, “a”, TRUE)*

• character

• numeric

• logical

• factor

4. consider a vector X<-c(“jan”,”feb”,”march”,”april”,”may”) and a vector Y<-X[c(TRUE,FALSE,TRUE,FALSE, FALSE)]. What will will the output of print(Y).*

• [1] “jan” “march” “may”

• [1] “jan” “march”

• [1] “feb” “april” “may”

• [1] “march” “april “may”

5. what will the output of X<-V1*V2  where V1<-c(1,2,3,4) and V2<-c(1,2)*

• [1] 1 4 3 8

• [1] 2 4 4 6

• error in code

• [1] 0 0 2 2

6. consider a list, list1<- list(“Sam”, “Green”, c(8,2,67), TRUE, 51.99, 11.78,FALSE).  what will be the output of list1[[3]][1]*

• [1] “Green”

• [1] 8 2 67

• ERROR

• [1] 8

7. Which of the following is a non-homogeneous data structure in R*

• vector

• list

• matrix

• array

8. consider a data frame named emp.data (below), what will be the output of emp.data[2:3,2]*

• [1] 1 [1] 1.414214 [1] 1.732051 [1] 2 [1] 2.236068

• [1] 1 [1] 2 [1] 3 [1] 4 [1] 5

• [1] 1.732051 [1] 1.414214 [1] 1.732051

• 1 4 6 16 25

13. command to a load a package to current R environment is:*

• library(package_name)

• install.packages(“package_name”)

• installed.packages(“package_name)

• load(package_name)

14. Select all packages included in “tidyverse” package*

• dplyr

• purrr

• readxl

• ggplot2

• MySQL

• tibble

• tidyr

15.  consider M1 <- matrix(c(1:9), nrow = 3, ncol =3, byrow= TRUE), what will be the output of M1[2,]*

• [1] 4 5 6

• [1] 1 2 3

• [1] 7 8 9

• [1] 2 4 6