D465 Data Applications - Set 1 - Part 3

Correct Answer: AVERAGEIF

AVERAGEIF computes the mean of cells in a range that meet a given criterion.

Correct Answer: INDEX and MATCH

INDEX combined with MATCH performs flexible lookups in any direction and is more robust than VLOOKUP, which can only look to the right of the lookup column.

Correct Answer: Returns one value if a condition is true and another if false

IF evaluates a logical condition and returns one value when it is true and a different value when it is false, enabling conditional logic.

Correct Answer: An absolute reference that does not change when copied

A dollar sign creates an absolute reference, locking the row and/or column so the reference does not shift when the formula is copied to other cells.

Correct Answer: Summarizing and aggregating data interactively

A PivotTable summarizes large datasets by grouping and aggregating values, letting users reorganize and explore data without formulas.

Correct Answer: read.csv()

read.csv() imports a comma-separated values file into an R data frame, the most common structure for tabular data in R.

Correct Answer: summary()

summary() returns descriptive statistics such as minimum, median, mean, and maximum for each column of a data frame.

Correct Answer: Ignores missing (NA) values in the calculation

Setting na.rm = TRUE tells the function to exclude NA (missing) values from the calculation, preventing the result from becoming NA.

Correct Answer: dplyr

The dplyr package provides a grammar of data manipulation, including filter, select, mutate, arrange, and summarize for transforming data frames.

Correct Answer: A table-like structure with rows and columns of possibly different types

A data frame is a two-dimensional table where each column can hold a different data type, the standard structure for datasets in R.