Unit 9 MSTAR-Style Practice Test — Form A

Relationships Between Two Variables · 4 questions · English only, like the real test · No timer — take the time you need.

These are MSTAR-style questions written for this curriculum to rehearse the format. They are not official Maryland assessment items. MSTAR — Maryland's new state test, first given in spring 2027 — uses the same kinds of questions you see here: selected response, select-all, two-part evidence questions, and written responses.

How this works: Answer every question, then press Submit & Grade. Selected-response parts grade instantly with an explanation for each; written responses go to your teacher. Your answers save on this device.

On the real MSTAR: math runs as three 40-minute sessions, in English, on a computer. Here there is no clock — practice the thinking first; the pacing comes with rehearsal.

Written responses: how should the explain-the-error questions be scored?

Instant scoring checks whether your explanation states the value and uses the reasoning the question is about. It matches words and numbers, so a right answer worded differently can score low — your teacher can always re-score it from the answer key.

16.AT.11Explore Relationships Between Two Variables

Select all that apply

Select ALL statements that name the independent variable correctly for their own situation.

A gardener chooses how many minutes to run the sprinkler, so the minutes the sprinkler runs is the independent variable. A student hangs different numbers of weights on a spring, so the stretch of the spring is the independent variable. Claire decides how long to jog, so the minutes she jogs is the independent variable. The total cost of the tickets is the independent variable, because the cost is the amount the problem asks for. A tray receives a set number of hours of sunlight each day, so the hours of sunlight is the independent variable and the plant height depends on it.

26.AT.11Analyze Graphs of Relationships Between Two Variables

Explain the error

Ramona is graphing sales at the stadium pretzel stand. Pretzels cost $6 each, and her table shows 1 pretzel with $6, 2 pretzels with $12, and 3 pretzels with $18. She labels the horizontal axis 'number of pretzels' and the vertical axis 'total cost'. For 3 pretzels she plots the point (18, 3).

Explain Ramona's misconception and give the correct ordered pair for 3 pretzels.

✍️ Written response — 2 points.

36.AT.11Write Equations to Represent Relationships Between Two Variables

Part A

A spin studio charges $7.50 for each class. Let n be the number of classes a member takes and let c be the total cost in dollars. Which equation represents the relationship?

c = 7.5 + n n = 7.5c c = n ÷ 7.5 c = 7.5n

Part B

Which reasoning justifies the equation chosen in Part A?

The number of classes is added to the price of one class, so 4 classes cost 7.5 + 4 = $11.50. The number of classes depends on the cost, so the classes belong alone on the left side of the equation. The $7.50 is shared among the classes, so 4 classes cost 7.5 ÷ 4 = $1.875 each. The $7.50 is charged for every single class, so the total is 7.5 times the classes; 4 classes cost 7.5 × 4 = $30.

46.AT.11Apply Two-Variable Relationships to Solve Problems

Part A

A bottling machine fills 45 bottles each minute. The relationship is b = 45m, where m is the number of minutes the machine runs and b is the number of bottles filled. The crew needs 1,800 bottles. How many minutes must the machine run?

40 minutes 45 minutes 1,755 minutes 81,000 minutes

Part B

Which reasoning justifies the number of minutes chosen in Part A?

The machine fills 45 bottles in a minute, so 1,800 bottles take 45 minutes. Multiply instead: 1,800 × 45 = 81,000, because a rate is always multiplied by the total. Substitute 1,800 for b to get 45m = 1,800, then divide both sides by 45, since 45 is multiplied by m. Subtract the rate: 1,800 − 45 = 1,755, because the machine already filled 45 bottles.