Nevada Grade 8 Math

A two-way table records two categorical variables for the same individuals. The invented survey below records whether each of twenty-four students joined an art club and whether each prefers a morning or afternoon exhibition. Each student appears in exactly one cell.

Try this original activity

Among club members, eight prefer morning and four prefer afternoon. Among nonmembers, four prefer morning and eight prefer afternoon. Construct the table and compare the proportion preferring morning within each membership group. What association can you describe, and what can you not conclude?

Work through the reasoning

Each membership group contains twelve students. Among club members, the morning proportion is 8/12 = 2/3, about 66.7%. Among nonmembers, it is 4/12 = 1/3, about 33.3%. Morning preference is therefore more common among members in this invented group. The difference is one-third, about 33.3 percentage points. The row totals are twelve and twelve, the column totals are also twelve and twelve, and the grand total is twenty-four. Those equal overall preference totals do not erase the within-group difference. The table describes an association in the supplied data; it does not establish that joining the club caused a preference or predict the preferences of all students.

Check the common mistake

Using 8/24 answers the share of the whole sample who are both members and morning-preferring. It does not answer the requested share among members. Start by naming the comparison group, then use its total as the denominator. Equal raw totals can be misleading when groups differ in size, which is why within-group relative frequencies help. This invented table has equal-sized groups, but the reasoning should still identify the group denominator rather than depend on that coincidence.

Try a related case

In another invented survey, nine of fifteen members and three of five nonmembers prefer morning. Both proportions equal 60%, despite different raw morning counts. Explain why comparing nine with three alone would incorrectly suggest a difference in the within-group preference rates.

Selected references from Nevada mathematics standards

The Nevada Department of Education’s mathematics directory links the Nevada Academic Content Standards for Mathematics. The selected references below identify the worked activity’s focus. The full document includes requirements, examples, mathematical practices, and grade-level progression. Read it alongside the school’s curriculum; one worked activity does not establish complete course alignment or grade-level proficiency.

Sources checked October 6, 2026. Read complete requirements, clarifications, limitations, and mathematical practices alongside the school’s sequence. This selected activity is an entry point for instruction.

Connect the explanation with practice

Use the lesson, worksheet, and quiz directory to choose a related skill. The existing resource links remain available; open each activity’s directions to understand its timer, tools, question count, and scoring.

The Nevada Department of Education identifies Smarter Balanced mathematics assessment for Grades 3–8, including Grade 8. Its public overview describes a computer-adaptive assessment. Confirm the learner’s assigned pathway and current school administration directions, including any alternate assessment pathway. Independently published practice may use its own timer, tools, question count, and scoring; these are not official administration specifications or a prediction of a state performance level. Read the current Nevada assessment overview.

Read Nevada mathematics guidance for later guidance. Keep one example of the student’s reasoning with the practice result. Choose a smaller model, a related question, or a new context according to the difficulty revealed in the worked activity.