UNC STOR 155: Introduction to Data Models and Inference
STOR 155 is UNC's introductory statistics course: descriptive statistics, probability basics, sampling distributions, confidence intervals, hypothesis testing, and regression. It serves business-track, social science, and quantitative-curious students, with software-based data work alongside the theory.
Fennie is independent and not affiliated with UNC Chapel Hill. This is an unofficial study guide.
What makes it hard
The course is cumulative with a predictable arc: descriptive statistics feels easy, probability gets skimmed, then inference arrives assuming both. Exams emphasize choosing the right procedure and interpreting results in context, precisely what formula-memorizers skip, and the Kenan-Flagler-bound students in the room keep the grading bar honest.
What you'll cover
- • Descriptive statistics and data visualization
- • Probability basics
- • Sampling distributions
- • Confidence intervals
- • Hypothesis testing
- • Correlation and regression
The STOR 155 study guide
How to study for UNC STOR 155, step by step.
- 1
Give probability full effort while it's cheap
STOR 155's failure arc runs through a skimmed probability unit that inference later assumes. The probability weeks are the foundation, so treat them as the course's real start.
- 2
Practice scenario-to-procedure matching
Given a described study, name the right interval or test and the reason before computing. Exams grade that selection step heavily, and it's the skill rereading formulas never builds.
- 3
Write a plain-English sentence for every result
Each practiced interval or test ends with one sentence of interpretation in context. That's the format exam questions reward, and the habit is what makes the concepts stick.
- 4
Do the software work early in the week
Data assignments surface confusion while there's still time to ask. Deadline-night software sessions convert fixable gaps into permanent ones.
- 5
Fold old units into every week's review
Inference assumes probability and sampling distributions stay warm. A few earlier-unit questions per week keeps nothing cold when the cumulative exams need everything.
Today
Today's STOR 155 plan
What a Fennie Daily Plan looks like for STOR 155. Yours is built from your own syllabus and adapts every day to your deadlines and progress.
First plan free, no card required. Fennie is independent and unaffiliated with your school.
FAQ
Is STOR 155 at UNC hard?
Manageable but unforgiving of gaps: every unit builds on the last, and students who skim probability rarely recover when inference arrives. The exams reward procedure selection and plain-English interpretation over computation, which surprises formula-focused studiers.
Do I need STOR 155 for Kenan-Flagler?
A statistics course is part of the standard pre-business preparation, and STOR 155 is the common choice. Business admission weighs early-coursework grades, so treat it as a course that counts twice. Verify the current Kenan-Flagler requirements as you plan.
Do I need calculus for STOR 155?
No. Algebra suffices, and the challenge is conceptual rather than computational: what sampling distributions, intervals, and tests mean, and which applies when. Students wanting the calculus-based treatment of probability take STOR 435 later instead.