R - Quiz

Quiz

Question 1

The expression

2**4

returns:

• 16

Question 2

We want to select two columns from a data frame called Clients, which expression is correct:

• Clients[,c(1,2)]

Question 3

What is the value of the expression

2+NA

• NA

apply

Question 4

If you want to calculate mean for each level in a factor, you would use which function:

• tapply

Question 5

We toss a fair coin 16 times, how to calculate probability of getting 7 or less tails

• pbinom(7,prob=0.5,size=16)

Question 6 We want to compare two means, which is the best function to use:

• meantest

Question 7 In order to add rows to a data frame which function is the most appropriate:

• addrows

Question 8 If you want to plot a bar chart, which function would you use:

• barplot