1. What is the correct output of the command is.na( c(4,5,NA))?

(a) FALSE FALSE TRUE (b) FALSE TRUE TRUE

(c) FALSE TRUE FALSE (d) TRUE FALSE TRUE

2. Which one of the following functions displays the variables of the given dataset?

(a) summary() (b) names()

(c) str() (d) install()

3. Which one of the following functions displays the structure of the given dataset?

(a) summary() (b) names()

(c) str() (d) install()

4. Which one of the following functions returns the number of categorical value after counting

it?

(a) table(dataset$variablenames) (b) table(dataset.variablenames)

(c) table(dataset) (d) table(variablenames)

5. How many rows are returned by the head() or tail() function by default?

(a) 1 (b) 4

(c) 6 (d) 5

6. Which one of the following functions returns the bottom five rows of the dataset ‘Mobile’?

(a) head(Mobile) (b) head(Mobile, 5)

(c) tail(Mobile) (d) tail(Mobile,5)