1.1.2

Question 1

What does the %>% symbol do?

Answer 1

Takes the output on the LHS and inputs it on the RHS

Question 2

What is an example of the %>% symbol in use?

Answer 2

library(tidyverse)
starwars2 %>%
summary()

Question 3

Give 2 examples to show the difference between inside-out and left-to-right code

Answer 3

Inside-out
summary(as.factor(starwars2$homeworld))

Left-to-right
starwars2$homeworld %>%
as.factor() %>%
summary()

Question 4

What does summary() provide for continuous variables?

Answer 4

Numeric descriptions of the distribution of values in each variables

Question 5

What does the distribution of a variable show?

Answer 5

The frequency of different values

Question 6

What is a frequency distribution?

Answer 6

An overview of all values in some variable and how many times they occur

Question 7

How can we access the frequencies of different response levels of a variable in a dataframe?

Answer 7

dataframe %>%
count(variable name)

Question 8

What is the mode and what type of data is it used to measure central tendency for?

Answer 8

The most frequent value
Unordered categorical data

Question 9

What is relative frequency distribution, what does it show, and how can it be written?

Answer 9

Percentage of respondents in each category
Proportion of times each value occurs
Decimals, fractions, percents

Question 10

What are two ways we can calculate the relative frequency distributions in a dataframe?

Answer 10

Make a frequency table
freq_table$n/sum(freq_table$n)
OR
freq_table <-
dataframe %>%
count(variable name) %>%
mutate(
prop = n/sum(n)
)

Question 11

How can we plot values in a bar chart?

Answer 11

ggplot(data = dataframe, aes(x = entry, y = entry)) +
geom_col()

Question 12

How can we change the axis labels?

Answer 12

labs(title = “entry”, x = “entry”, y = “entry”)

Question 13

How can we make a scatterplot?

Answer 13

ggplot(data = dataframe)
geom_point

Question 14

How can we change the limits of the axis?

Answer 14

ylim(min, max)

Question 15

How can we remove the legend?

Answer 15

theme(legend.position = “none”)

Question 16

How can we add the percentage and cumulative percentage of each response to a table?

Answer 16

dataframe %>%
count(entry) %>%
mutate(
percent = n/sum(n)*100
cumulative_percent = cumsum(percent)
)

Question 17

What is the median?

Answer 17

The middle value

Question 18

What does count() do?

Answer 18

Counts the number of occurrences of each unique value in a variable

Question 19

What does mutate() do?

Answer 19

Adds new variables/modifies existing variables in a dataframe

Question 20

What do min() and max() do?

Answer 20

Return the minimum/maximum value of a variable