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### Unit 6: Lesson 5

Lesson 6: The slope of a fitted line

# Scatter plot: smokers

Sal chooses the scatter plot that shows that smoking rate drops by 0.5 point each year. Created by Sal Khan.

## Want to join the conversation?

• This is hard is there an easier way to do this.??
• Stick with it! You'll get it. What may help is to brush up on basic shapes of functions (ie: linear= straight line, logarithmic, exponential, polynomial, etc). These are taught in Pre-Calc and Calc classes already. A suggestion to Khan Academy might be to do a quick video and practice review section at the beginning of this section to review what linear/ non-linear functions look like in graph (non-scatter) form...and since I suggested it, I'll even do the video if you want me to, just show me the tools and code to upload the wmv. :-)
• At 00:9, sal says linear association what does that mean?
• The scatter plot looks like a linear function. It is almost a straight line.
• At , what does Sal mean by an outlier in the graph?
• Something that doesn't fit in with the rest of the points
• anyone from 2022 i understand perfectly
• Wait so how would you just identify a linear or not linear if 2 look the same like graph 1 and graph 2.
• Graph 1 and graph 2 are both linear. You cannot identify them with linear association.
Instead, in the question, it said that percent drops by 0.5 point each year.
You have to compare two different points and figure it out.
• why does khan academy exist
• bc they wanna make money off us dumb kids
(1 vote)
• At 00:9, sal says linear association what does that mean?
• A linear association is when the points on the graph line up in just about a straight line, hence "linear."
(1 vote)
• I'm from India.
I also see some people smoking for a living. Really they should stop.
anyways, nice video! :)
• At , why does graph 3 has outliers?
• One of the points doesn't fit in nicely when you draw a line close to the rest of the points.
(1 vote)
• Can anyone tell me the definition of outliers? I keep on seeing i on here and in class. Thanks!!
(1 vote)
• Outliers are numbers that 'stick out; among the rest.

1 2 50,000,000,000,000,000,000
^ A rather exaggerated example but it gets my point across ^^;

But more realistically, you would see
51, 52, 150

They're the huge numbers (or even small numbers) that stick out. They also mess you up when you calculate the mean, so be careful!

^-^