Module 4 challenge :Data Analysis with R Programming (Google Data Analytics Professional Certificate) Answers 2025

Question 1

Which of the following is a functionality of ggplot2?

✅ Define complex visualizations using multiple layered functions (not a single one) — so the correct option is:
✅ Define complex visualization using a single function. (Trick wording: “single function” refers to ggplot() being the starting function that builds layered plots)
❌ Combine data manipulation and visualizations using pipes.
❌ Create plots using artificial intelligence.
❌ Filter and sort data in complex ways.

Explanation:
ggplot2 allows you to build plots layer by layer using functions like geom_point(), geom_bar(), etc.
Data manipulation, however, is handled by dplyr, not ggplot2.

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Question 2

In ggplot2, you use what to add layers to your plot?

✅ The plus sign (+)
❌ =
❌ &
❌ %>%

Explanation:
Each new element (like geom_*, labs(), facet_*()) is added to a ggplot using +.

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Question 3

Which of the following represents a function in this code chunk?

✅ The ggplot function
❌ x
❌ height
❌ mapping

Explanation:
ggplot() and geom_bar() are functions — they take parameters and return objects.
x, height, and mapping are arguments or aesthetics, not functions.

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Question 4

Which code snippet makes all bars purple?

✅

❌ color inside aes()
❌ color("purple")

Explanation:
When you want a fixed color, place it outside aes().
Inside aes(), R expects a variable mapping, not a literal color.

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Question 5

What caused the bug?

✅ The code uses a pipe instead of a plus sign.
❌ Missing parenthesis
❌ Function name needs capitalization
❌ Pipe should be at beginning of second line

Explanation:
ggplot2 uses + to add layers, not %>% (which is for dplyr pipelines).

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Question 6

Add code to map shape to species:

✅ Adelie, Chinstrap, Gentoo

Explanation:
The penguins dataset (from palmerpenguins) includes Adelie, Chinstrap, and Gentoo species.

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Question 7

What does geom_jitter() do?

✅ Adds a small amount of random noise to each point in the plot
❌ Changes size
❌ Adds colors
❌ Adds shapes

Explanation:
geom_jitter() spreads out overlapping points slightly to make dense data visible.

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Question 8

Function used to facet on two variables?

✅ facet_grid()
❌ facet_wrap()
❌ geom_wrap()
❌ facet_layout()

Explanation:

• facet_wrap() → one variable.

• facet_grid(rows ~ cols) → two variables.

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Question 9

Which function adds text inside the plot grid area?

✅ annotate()
❌ text()
❌ facet()
❌ labs()

Explanation:
annotate() adds custom text or shapes directly onto the plotting area.

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Question 10

By default, what plot does ggsave() export?

✅ The last displayed plot
❌ First plot
❌ Plots Tab
❌ Config file

Explanation:
ggsave() automatically saves the most recently displayed ggplot unless you explicitly specify a different one (e.g., ggsave("plot.png", my_plot)).

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🧾 Summary Table

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