RICAS Grades 6-8 Statistics and Probability Practice

Statistics and Probability skills

develop understanding of statistical variability

summarize and describe distributions

investigate chance processes and probability models

use random sampling to draw inferences about a population

Standards basis

Common Core State Standards (CCSS-M), via the Massachusetts Curriculum Framework for Mathematics (2017) adopted/used for RICAS alignment — Rhode Island

How the RICAS reports it

RICAS mathematics in grades 3–8 is the Rhode Island-administered version of Massachusetts MCAS math, and RIDE states the Massachusetts framework is strongly aligned with Rhode Island’s Common Core-based mathematics standards. The released-item documents report results under the same framework domains used by the Massachusetts Curriculum Framework for Mathematics.

Blueprint & weighting

The official source reviewed here did not publish domain percentage weights in the pages/documents retrieved. The released-item documents do state that mathematics results are reported under five MCAS reporting categories identical to the framework domains.

Official sources

Rhode Island Department of Education — Released Items & Practice Tests
Rhode Island Department of Education — Mathematics
Massachusetts Department of Elementary and Secondary Education — Massachusetts Mathematics Curriculum Framework (2017)

8 free questions · 0/0 correct

Practice playmedium

A coach recorded how many goals the team scored in each of $16$ games. The frequency table shows the results.
$\begin{array}{c|c} \text{Goals scored} & \text{Number of games} \\ \hline 1 & 2 \\ 3 & 4 \\ 5 & 4 \\ 7 & 3 \\ 9 & 3 \end{array}$

What is the mean number of goals scored per game?

Multiply each goal total by its frequency and add: $(1 \times 2) + (3 \times 4) + (5 \times 4) + (7 \times 3) + (9 \times 3) = 82$ . With $16$ games, the mean is $\dfrac{82}{16} = 5.125$ goals per game.

Practice playeasy

Mia can pick from $5$ shirts and $2$ hats. How many different (shirt, hat) outfits are possible?

By the counting principle: $5 \times 2 = 10$ .

Practice playeasy

Four students answered the statistical question "How many letters are in your first name?" The data are $7, 3, 5, 11$ . What is the median of the data?

The median describes the center. With an even number of values, put them in order and average the two middle values. In order: $3, 5, 7, 11$ . The two middle values are $5$ and $7$ , and $\dfrac{5 + 7}{2} = 6$ .

Practice playeasy

Coach Rivera brainstorms four questions:

• How many push-ups can each player on my team do?
• How many push-ups did the team captain do today?
• How many sit-ups can each player on my team do?
• How many laps can each player on my team run?

How many of the four are statistical questions?

A statistical question anticipates variability. Asking how many push-ups, sit-ups, or laps each player can do asks about every player, so the answers can differ from player to player. Asking how many push-ups the team captain did today asks about one person on one day, so it has one answer. That makes $3$ statistical questions.

Practice playeasy

A shipping clerk weighs five packages at $50$ , $55$ , $60$ , $65$ , and $70$ pounds. The $70$ -pound package is removed from the data set. How does this affect the mean?

The mean of the original five weights is $\dfrac{50+55+60+65+70}{5}=60$ pounds. Because $70>60$ , removing the heaviest package lowers the mean.

Practice playeasy

Five quiz scores are $82\textsf{,}$ $75\textsf{,}$ $90\textsf{,}$ $85\textsf{,}$ and $68\textsf{.}$ What is the mean score?

Mean $= \dfrac{82 + 75 + 90 + 85 + 68}{5} = \dfrac{400}{5} = 80$ .

Practice playeasy

Find the mean of the data set 6, 6, 9, 12, 12.

Mean $= \dfrac{6+6+9+12+12}{5} = 9$ .

Practice playeasy

The ages, in years, of seven students are $12\textsf{,}$ $7\textsf{,}$ $15\textsf{,}$ $9\textsf{,}$ $18\textsf{,}$ $10\textsf{,}$ and $20\textsf{.}$ What is the median age?

In order, the values are $7\textsf{,}$ $9\textsf{,}$ $10\textsf{,}$ $12\textsf{,}$ $15\textsf{,}$ $18\textsf{,}$ $20\textsf{.}$ The median is the middle value, $12\textsf{.}$

RICAS Grades 6-8 Statistics and Probability. Practice it free.

Statistics and Probability skills

develop understanding of statistical variability

summarize and describe distributions

investigate chance processes and probability models

use random sampling to draw inferences about a population

Topics mapped to this domain

Central Measures from Tally Charts (ACT)

Compound probability

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

One-event probability word problems

Probability basics

Probability from number sets

Probability of simple events

8 free questions · 0/0 correct

Turn statistics and probability into game time.

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