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.IS.2.a

Describe the shape, center, and spread of the sampling distribution of a mean within the context of a problem.

Example Problems

A taco stand tops a certain taco with 5 slices of jalapeño. The slices have a mean mass of

\mu = 2.4

grams and a standard deviation of

\sigma = 0.3

grams. We can assume that the masses of the slices are independent from each other. Let

T

be the total mass of the jalapeño slices on a randomly chosen taco.

Find the mean of T,

\mu_T

.

A bakery decorates a muffin with 7 chocolate chips. The chips have a mean mass of

\mu = 0.9

grams and a standard deviation of

\sigma = 0.1

grams. We can assume that the masses of the chips are independent from each other. Let

T

be the total mass of the chocolate chips on a randomly chosen muffin.

Find the mean of

T

,

\mu_T

.

At a coffee shop, a popular iced latte includes

3

shots of espresso. The shots have a mean volume of

\mu = 30

milliliters and a standard deviation of

\sigma = 2

milliliters. We can assume that the volumes of the shots are independent from each other. Let

T

be the total volume of the shots in a randomly chosen iced latte.

Find the mean of T,

\mu_T

.

Khan Academy Resources

Sample variance Sample standard deviation and bias

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