Quiz 2 :Developing Data Products (Data Science Specialization) Answers 2025

Question 1 – What is rmarkdown? (Check all that apply)

✅ A format that can be interpreted into markdown (which is a simplified markup language).
✅ A simplified format that, when interpreted, incorporates your R analysis into your document.
❌ A form of LaTeX typesetting.
❌ A simplified XML format that can be interpreted into R.

Explanation:
R Markdown combines plain text (Markdown syntax) with embedded R code chunks, allowing automatic integration of code results (figures, tables, etc.) into reports. It’s not XML or LaTeX itself (though it can render to LaTeX via pandoc).

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Question 2 – Which chunk option prevents R code from being shown in the output?

✅ echo = FALSE
❌ cache = FALSE
❌ comment = FALSE
❌ eval = FALSE

Explanation:
echo = FALSE hides the code, but still shows results/plots.

• eval = FALSE prevents running code.

• cache affects speed (stores results).

• comment controls how output is prefixed.

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Question 3 – Which chunk option prevents code from being run/interpreted?

✅ eval = FALSE
❌ run = FALSE
❌ cache = FALSE
❌ eval = NULL

Explanation:
Setting eval = FALSE means R will not execute the code in that chunk—it just displays the code (if echo=TRUE).

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Question 4 – What is leaflet? (Check all that apply)

✅ An R package interface to the JavaScript library of the same name.
✅ A JavaScript library for creating interactive maps.
❌ A tool for reproducible documents.
❌ An R package for creating 3D rendered isomaps.

Explanation:
Leaflet is a popular JavaScript library for interactive web maps, and the R leaflet package exposes this functionality inside R. It’s not for 3D rendering or reproducible reports.

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Question 5 – The R command

is equivalent to what? (Check all that apply)

✅ leaflet(df) %>% addTiles()
✅ addTiles(leaflet(df))
❌ leaflet(addTiles(df))
❌ df(leaflet(addTiles()))
❌ addTiles(leaflet(df()))

Explanation:
The pipe operator %>% forwards the left-hand object (df) into the first argument of the next function, so both these forms are equivalent:

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Question 6 – If I want to add popup icons to my leaflet map in R, I should use:

✅ addMarkers
❌ dplyr
❌ leaflet
❌ addTiles

Explanation:
addMarkers() is the Leaflet function used to add pins/markers (which can include popups or icons) to maps.

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🧾 Summary Table