WGU D465 - DATA APPLICATIONS.
EXAM QUESTIONS AND ANSWERS | 2026
UPDATE | 100% CORRECT.
R and Python similarities - ANS Both widely used in data science with extensive libraries.
R unique challenges - ANS Steeper learning curve, limited web dev capabilities.
Advantage of storing code in R - ANS Allows reproducibility and collaboration among
analysts.
Programming languages and use cases - ANS Python: web dev, data science, ML, automation.
MIN function in spreadsheets - ANS Returns the smallest value in a cell range.
COUNTIF function in spreadsheets - ANS Counts cells meeting a specified condition.
Pivot table elements - ANS Rows, columns, values, filters for data aggregation.
SELECT command in SQL - ANS Retrieves data from one or more database tables.
JOIN commands in SQL - ANS INNER, LEFT, RIGHT, FULL OUTER JOIN types.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 27
,Delimiter for code chunks - ANS Triple backticks or markup to define code sections.
Output formats for documents - ANS HTML, PDF, Word (docx), Markdown.
Presentation formats - ANS Slides, Dashboards, Interactive web apps.
Knit button in R - ANS Compiles R Markdown into desired output formats.
Symbol for comments in R - ANS Pound sign (`#`) precedes comments in R.
Nested function usage - ANS Simplifies operations, improves code readability.
Logical operators - ANS AND (&&), OR (||), NOT (!).
Advantage of tidyverse - ANS Cohesive data manipulation packages in R.
Functions in ggplot2 - ANS ggplot(), geom_point(), geom_line(), aes().
Plus sign in ggplot2 - ANS Adds layers to ggplot objects for customization.
Common errors in ggplot2 - ANS Incorrect aesthetic mappings, syntax misunderstanding.
Basic aesthetic attributes in ggplot2 - ANS x-axis, y-axis, color for plot customization.
Smoothing line usage - ANS Visual representation of trends in data.
dplyr filter() function - ANS Subset rows based on specific conditions in R.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 27
, VLOOKUP function in spreadsheets - ANS Searches for values in a vertical column.
Locking table array in VLOOKUP - ANS Prevents range changes for formula accuracy.
Different JOIN functions in SQL - ANS INNER, LEFT, RIGHT, FULL OUTER JOIN types.
COUNT vs. COUNT DISTINCT in SQL - ANS COUNT: total rows, COUNT DISTINCT: unique
values.
SELECT statement usage in SQL - ANS Retrieving data from one or more tables.
FROM statement in SQL - ANS Specifies tables for data retrieval in SQL queries.
Tibbles vs. data frames - ANS Modernized data frames with improved features.
Main operators in R - ANS Arithmetic, relational, logical, assignment operators.
sample() function for biased data - ANS Creates random unbiased data samples.
Fill in the blank: The spreadsheet function _____ returns the number of cells within a range that
match a specified value.
COUNTIF
ARRAY
COUNT DISTINCT
VALUE - ANS COUNTIF
What is an example of an array in a spreadsheet?
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 27
EXAM QUESTIONS AND ANSWERS | 2026
UPDATE | 100% CORRECT.
R and Python similarities - ANS Both widely used in data science with extensive libraries.
R unique challenges - ANS Steeper learning curve, limited web dev capabilities.
Advantage of storing code in R - ANS Allows reproducibility and collaboration among
analysts.
Programming languages and use cases - ANS Python: web dev, data science, ML, automation.
MIN function in spreadsheets - ANS Returns the smallest value in a cell range.
COUNTIF function in spreadsheets - ANS Counts cells meeting a specified condition.
Pivot table elements - ANS Rows, columns, values, filters for data aggregation.
SELECT command in SQL - ANS Retrieves data from one or more database tables.
JOIN commands in SQL - ANS INNER, LEFT, RIGHT, FULL OUTER JOIN types.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 27
,Delimiter for code chunks - ANS Triple backticks or markup to define code sections.
Output formats for documents - ANS HTML, PDF, Word (docx), Markdown.
Presentation formats - ANS Slides, Dashboards, Interactive web apps.
Knit button in R - ANS Compiles R Markdown into desired output formats.
Symbol for comments in R - ANS Pound sign (`#`) precedes comments in R.
Nested function usage - ANS Simplifies operations, improves code readability.
Logical operators - ANS AND (&&), OR (||), NOT (!).
Advantage of tidyverse - ANS Cohesive data manipulation packages in R.
Functions in ggplot2 - ANS ggplot(), geom_point(), geom_line(), aes().
Plus sign in ggplot2 - ANS Adds layers to ggplot objects for customization.
Common errors in ggplot2 - ANS Incorrect aesthetic mappings, syntax misunderstanding.
Basic aesthetic attributes in ggplot2 - ANS x-axis, y-axis, color for plot customization.
Smoothing line usage - ANS Visual representation of trends in data.
dplyr filter() function - ANS Subset rows based on specific conditions in R.
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 27
, VLOOKUP function in spreadsheets - ANS Searches for values in a vertical column.
Locking table array in VLOOKUP - ANS Prevents range changes for formula accuracy.
Different JOIN functions in SQL - ANS INNER, LEFT, RIGHT, FULL OUTER JOIN types.
COUNT vs. COUNT DISTINCT in SQL - ANS COUNT: total rows, COUNT DISTINCT: unique
values.
SELECT statement usage in SQL - ANS Retrieving data from one or more tables.
FROM statement in SQL - ANS Specifies tables for data retrieval in SQL queries.
Tibbles vs. data frames - ANS Modernized data frames with improved features.
Main operators in R - ANS Arithmetic, relational, logical, assignment operators.
sample() function for biased data - ANS Creates random unbiased data samples.
Fill in the blank: The spreadsheet function _____ returns the number of cells within a range that
match a specified value.
COUNTIF
ARRAY
COUNT DISTINCT
VALUE - ANS COUNTIF
What is an example of an array in a spreadsheet?
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 27
