Is Goblins free for teachers?

Yes. Goblins offers a generous free tier that includes 1 live feedback assignment per week, insights on student mastery and replays, and the ability to upload your own content. The Max plan adds unlimited assignments, superadaptive mode, grade exports, standards growth reports, and SSO/LMS integration, with per-student pricing for schools and districts.

How does Goblins work?

Three simple steps: (1) Share an assignment from thousands of standards-aligned topics using a share code. (2) Students speak and draw their thinking naturally, and Goblins responds with Socratic questioning that sounds just like their teacher. (3) Teachers get real-time formative insights showing what students struggle with and suggestions to inform instruction.

Does Goblins prevent cheating?

Yes. Goblins uses a purpose-trained AI model that evaluates cheating signals in real time. It can detect when students are copying answers, using external tools inappropriately, or not genuinely working through problems. Copy-pasting answers is also blocked.

Can I use my own voice with Goblins?

Yes. Teachers can record their voice and take a selfie to create a custom 3D avatar in about 30 seconds. Students then hear help in their own teacher's voice and see a familiar face, making the experience more personal and effective.

What math levels does Goblins cover?

Goblins covers math from Grade 5 through AP Calculus, including thousands of standards-aligned topics. Teachers can also upload their own content for custom assignments at any level.

Is Goblins FERPA compliant?

Yes. Goblins is FERPA and state compliant. Student data privacy and security are a top priority.

Does Goblins support English Language Learners?

Yes. Goblins supports 30+ languages so teachers don't have to translate every worksheet. It is especially helpful for ELL students who need accessible math instruction in their native language.

PS.ED.3

Construct simulated sampling distributions of sample proportions and use sampling distributions to identify which proportions are likely to be found in a sample of a given size.

Example Problems

A credit union claims that 35% of its roughly 70,000 cardholders use automatic payments. A financial blogger takes a simple random sample of 280 cardholders and asks about autopay.

Assuming the credit union's claim is correct, what is the probability that the sample result is within 4 percentage points of the 35% claim?
Round your answer to the nearest hundredth.

A newsletter team claims that 47% of its more than 200,000 subscribers opened the most recent email. An auditor takes a simple random sample of 160 subscribers and checks whether they opened it.

Assuming the team's 47% claim is correct, what is the approximate probability that more than 50% of the sample opened the email?
Round your answer to the nearest hundredth.

A factory's defect rate for microchips has been 2.4%. After installing a new quality-control system, engineers want to test if the defect rate has changed. In a production run of 3,000 chips, 81 were defective (2.7%).

Let

p

represent the proportion of defective microchips with the new system.

State the alternative hypothesis,

H_a

, for this test.

Khan Academy Resources

Absolute value graphs review Scale & reflect absolute value graphs Shift absolute value graphs Shifting absolute value graphs Scaling & reflecting absolute value functions: graph Scaling & reflecting absolute value functions: equation

1-on-1 AI tutoring aligned to PS.ED.3. Instant help for students, real-time insights for teachers.

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