Descriptive Statistics
Use R’s built-in functions to measure central tendencies and variability in datasets.
Descriptive Statistics is a free R Academy lesson on CoddyKit — lesson 1 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the R Academy learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
1
Introduction to Descriptive Statistics
Descriptive statistics summarize and describe features of a dataset. They provide insights into the data distribution and variability.
2
Calculating Mean
The mean (average) is calculated using the mean() function.
data <- c(10, 20, 30, 40, 50)
mean(data)3
Calculating Median
The median is the middle value in a sorted dataset.
median(data)4
Calculating Mode
R does not have a built-in mode function, but you can compute it manually.
mode_function <- function(x) {
uniq_x <- unique(x)
uniq_x[which.max(tabulate(match(x, uniq_x)))]
}
mode_function(data)5
Calculating Standard Deviation
The standard deviation measures the spread of data points.
sd(data)6
Calculating Variance
The variance quantifies the dispersion of data points.
var(data)7
Calculating Summary Statistics
The summary() function provides an overview of descriptive statistics.
summary(data)8
9
Calculating Quantiles
Use quantile() to find quartiles and percentiles in a dataset.
quantile(data, probs = c(0.25, 0.5, 0.75))10
Summary
In this lesson, you learned:
- How to calculate mean, median, and mode.
- How to compute standard deviation and variance.
- How to use
summary()andquantile()for deeper insights.
Frequently asked questions
Is the “Descriptive Statistics” lesson free?
Yes — the full text of “Descriptive Statistics” is free to read here on the web, and the R Academy course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the R Academy course, upgrade to CoddyKit PRO.
What will I learn in “Descriptive Statistics”?
Use R’s built-in functions to measure central tendencies and variability in datasets. You practise R Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start R Academy?
No prior experience is required. R Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Descriptive Statistics” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this R Academy lesson?
Yes. Every R Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Descriptive Statistics
- Probability Distributions
- Hypothesis Testing