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.

What grade level is PS taught?

This standard is part of the PS curriculum in South Carolina College- and Career-Ready Standards - Mathematics.

PS: Probability and Statistics

Probability and Statistics

Print

PS.SPCRConditional Probability and Rules of Probability PS.SPIDInterpreting Data PS.SPMDUsing Probability to Make Decisions PS.SPMJMaking Inferences and Justifying Conclusions

Example Problems

How many unique ways are there to arrange the letters in the word BALLOON?

Isabella is studying the relationship between daily study hours and exam score. She records data for a random sample of 22 students. Here is computer output from a least-squares regression analysis on her sample:

Predictor	Coef	SE Coef	T	P
Constant	52.30	5.05	10.36	0.00
Study hours	4.52	1.05	4.30	0.00

S = 8.80 \quad R\text{-sq} = 58.6\%

Assume that all conditions for inference have been met.

Write the expression for a 99% confidence interval for the slope of the least squares regression line.

A significance test is going to be performed using a significance level of

\alpha = 0.05

. Suppose that the alternative hypothesis is actually true.

If the significance level was raised to

\alpha = 0.10

, which of the following would be true?
The power of the test would: increase, decrease, or stay the same.

A streaming company reviews 1,200 randomly selected viewing sessions from millions of sessions and finds that 108 experienced noticeable buffering.

Based on this sample, what is the 95% confidence interval for the proportion of sessions that experience buffering?
Round your answers to the nearest thousandth.

Two fair six-sided dice are rolled.

What is the probability that both dice show an even number?
Round your answer to two decimal places.

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

Used in classrooms by 100,000+ students at Baltimore County, Plano ISD, Deer Valley USD, KIPP, and districts nationwide.

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