Built-in AI tutor. Open it with the "Ask AI" button at the bottom-right. When Chrome can run it on your device, it does. Otherwise your question, and what you have typed or picked on this page, goes to the class AI server. Either way, the course saves your questions and the tutor's replies. It coaches you through the work and will not hand you the answer.
A scatter shows whether two measures move together. A linear trendline is a
regression Excel fits for you, its slope is the direction, its R² is how tightly the
points hug the line. Pick a dataset, predict the fit, then reveal it.
Trendline:
R²:
Mean x / mean y:
Correlation r:
The point
Cycle through Anscombe I to IV: every one has the same mean, variance, correlation,
and trendline, but four completely different shapes. The trendline is a model of the data,
not the data. Plot before you trust a number. Then compare the Strong / Weak / None
sets to feel what R² is measuring.