CMAS Grades 6-8 Statistics & Probability Practice

Statistics & Probability skills

Develop understanding of statistical variability

Summarize and describe distributions

Use random sampling to draw inferences about a population

Investigate patterns of association in bivariate data

Standards basis

Colorado Academic Standards (mathematics) — Colorado

How the CMAS reports it

CMAS is Colorado’s statewide summative assessment system aligned to the Colorado Academic Standards rather than a national framework like SBAC or NAEP. The official CMAS page and Colorado standards materials indicate the math assessment is built from Colorado Academic Standards, but the retrieved official CMAS page did not expose a separate math blueprint document.

Blueprint & weighting

No official CMAS math domain weighting/percent-of-items blueprint was available in the retrieved primary CMAS materials.

Official sources

Colorado Department of Education CMAS page
Colorado Department of Education Colorado Academic Standards and Essential Skills page

8 free questions · 0/0 correct

Practice playeasy

A student tracked minutes spent studying each night for $16$ nights. The frequency table shows the results.
$\begin{array}{c|c} \text{Minutes studied} & \text{Number of nights} \\ \hline 10 & 2 \\ 20 & 4 \\ 30 & 3 \\ 40 & 5 \\ 50 & 2 \end{array}$

What is the median number of minutes studied per night?

Expand to $16$ values: $10, 10, 20, 20, 20, 20, 30, 30, 30, 40, 40, 40, 40, 40, 50, 50$ . The $8$ th and $9$ th values are both $30$ , so the median is $30$ minutes.

Practice playeasy

The statistical question "How many minutes is your ride to school?" produced the data $3, 8, 10, 15$ . What is the range of the data?

The range describes the spread: greatest value minus least value. $15 - 3 = 12$ .

Practice playeasy

A student is writing questions about trees. Which of these is a statistical question?

A statistical question anticipates variability: many people or things can give different answers. "How tall are the trees in the park?" asks about many trees, so the heights can differ. It is a statistical question.

Practice playmedium

A cyclist records five ride distances, in miles: $12$ , $15$ , $18$ , $21$ , and $24$ . Another ride distance is added to the data set, but its length is not given. How does this affect the mean?

The mean of the five known distances can be found, but the effect of the change depends on the unknown sixth distance. Without that value, the new mean cannot be determined.

Practice playeasy

Seven morning temperatures, in degrees Fahrenheit, are $62\textsf{,}$ $64\textsf{,}$ $66\textsf{,}$ $75\textsf{,}$ $70\textsf{,}$ $72\textsf{,}$ and $67\textsf{.}$ What is the mean temperature?

Mean $= \dfrac{62 + 64 + 66 + 75 + 70 + 72 + 67}{7} = \dfrac{476}{7} = 68$ .

Practice playeasy

Find the median of 2, 4, 6, 8.

Order the data and take the middle value(s): median $= 5$ .

Practice playeasy

Five afternoon temperatures, in degrees Fahrenheit, are $64\textsf{,}$ $78\textsf{,}$ $72\textsf{,}$ $60\textsf{,}$ and $66\textsf{.}$ What is the median temperature?

In order, the values are $60\textsf{,}$ $64\textsf{,}$ $66\textsf{,}$ $72\textsf{,}$ $78\textsf{.}$ The median is the middle value, $66\textsf{.}$

Practice playeasy

A random sample of 20 contained 5 successes. What is the sample proportion (as a simplified fraction)?

Proportion $= \dfrac{5}{20} = \dfrac{1}{4}$ .

CMAS Grades 6-8 Statistics & Probability. Practice it free.

Statistics & Probability skills

Develop understanding of statistical variability

Summarize and describe distributions

Use random sampling to draw inferences about a population

Investigate patterns of association in bivariate data

Topics mapped to this domain

Central Measures from Tally Charts (ACT)

Describing a Data Distribution

Identifying Statistical Questions

Mean change from data set edits

Mean from a data list

Measures of center and variability

Median from a data list

Sampling and inference

Scatterplots and trend lines

Two-way tables

8 free questions · 0/0 correct

Turn statistics & probability into game time.

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