Montana Math MT.PLUS.DATA.NORM.1

MathGrades 9–12Normal Distribution

The Standard

Determine if a data set is normally distributed.

2026 Montana Mathematics Content Standards · Data Reasoning

Teacher's field guide

What Students Need to Do: Students graph a data set and look for one central peak, roughly balanced sides, and fewer values toward both ends. They decide whether a normal model is reasonable, not whether the graph makes a perfect bell.
What Mastery Looks Like: Given a histogram, a student can say whether a normal model is reasonable and point to features of its shape. They can explain why a skewed or two-peaked graph is a poor fit.
Common Misconceptions: Students may call any symmetric graph normal, even one with two peaks. They may think matching mean and median prove a data set is normal. They may expect a small sample to make a perfectly smooth bell.
How to Assess It: A histogram has seven equal-width bins with counts 1, 3, 7, 11, 7, 3, 1. Would a normal model be reasonable? Name two features of the shape that support your answer.

Lesson moves

Measure 30 ruler-drop catches in centimeters, stack sticky notes in 5 cm bins, and check the histogram for one peak and tapering sides.
Show two symmetric histograms, one with one peak and one with two; ask students which could be normal and why.
Draw six histogram cards with bell-shaped, skewed, flat, and two-peaked examples; have pairs sort them by whether a normal model is reasonable.
Measure 30 used pencils, graph their lengths in 1 cm bins, and decide whether a normal model fits.

Free download

$Preview of the MT.PLUS.DATA.NORM.1 printable worksheet$

A ready-to-print activity worksheet aligned to MT.PLUS.DATA.NORM.1, with an answer key for the teacher on its own page. No account needed.

PDF, US Letter, prints cleanly in black and white.

Keep exploring

Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.