#0049

Grouped Summary by Category

MediumR15 min15 XP

Problem

Given a sales data frame with columns region and revenue, return the average revenue for each region.

Many interview and analytics tasks ask for one metric per group: average spend per segment, conversion by channel, revenue by region.

aggregate(revenue ~ region, data = sales, FUN = mean)

Example 1

InputSouth: 100, 300; North: 200, 600; West: 400

OutputSouth 200, North 400, West 400

Each group is averaged independently.

CodeR

sales <- data.frame(
  region = c("South", "North", "South", "West", "North"),
  revenue = c(100, 200, 300, 400, 600)
)

# write your code here

sales <- data.frame(
  region = c("South", "North", "South", "West", "North"),
  revenue = c(100, 200, 300, 400, 600)
)

# write your code here

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Three regions

Inputfive sales rows

ExpectedSouth mean 200, North mean 400, West mean 400

Group first, then calculate the mean inside each group.

Hidden Test Categories

Single-row groupRegions appearing out of orderDecimal revenue values