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.

AII.S-IC.B.4

Use data from a sample survey to estimate a population mean or proportion; develop a margin of error through the use of simulation models for random sampling.

Example Problems

A bakery's loaf weights (in grams) are normally distributed with a mean of

500 \text{ grams}

and a standard deviation of

18 \text{ grams}

. Suppose the bakery selects a random sample of

36

loaves and computes the sample mean weight.

What is the probability that the sample mean weight

\bar{x}

is within

2 \text{ grams}

of the population mean?
Round your answer to the nearest hundredth.

In a controlled process, pressure readings (in

\text{kPa}

) are normally distributed with a mean of

102 \text{ kPa}

and a standard deviation of

1.8 \text{ kPa}

. Suppose a technician records a random sample of 5 readings and computes the sample mean pressure.

What is the probability that the mean pressure from a sample of 5 readings

\bar{x}

exceeds

103 \text{ kPa}

P(\bar{x} > 103) = ?

Round your answer to the nearest hundredth.

A machine shop manufactures bolts whose diameters (in millimeters) are normally distributed with a mean of

10 \text{ mm}

and a standard deviation of

0.2 \text{ mm}

. Suppose inspectors measure a random sample of

4

bolts and compute the sample mean diameter.

What is the probability that the sample mean diameter

\bar{x}

is less than

9.95 \text{ mm}

P(\bar{x} < 9.95) = ?

Round your answer to the nearest hundredth.

Khan Academy Resources

Random number list to run experiment

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