Interpreting Trend Lines

What type of correlation does this graph have? Check ALL correct answers.

• positive

• negative

• linear

• non-linear

Answer explanation

A linear association doesn't have to be perfectly straight, just straight-ish.

Did you mark positive AND linear?

Tags

CCSS.HSF-LE.A.1B

How should we describe this correlation? Check ALL correct answers.

• linear

• nonlinear

• one outlier

• no association

Answer explanation

This data HAS an association--it's just not straight-ish, so it's a non-linear association.

Did you see the outlier in the bottom left corner?

Which is the best estimate for the SLOPE of this trend line? Click the graph to see it.

• 50

• 75

• 0.02

• 2

Answer explanation

The slope is the ratio of rise to run for the line.

We also call slope the rate of change.

Tags

CCSS.8.EE.B.5

Which is the best estimate for the y-intercept of the trend line?

• 50

• 25

• 1

• 75

Answer explanation

The y-intercept is where the line crosses the y-axis.

Sammy is selling his comic book collection on the internet. The scatterplot shows how many comic books he has left at the end of each day. Using the trend line, how many comic books should Sammy have left after 6 days?

• 15

• 10

• 30

• 8

Which scatter plot could have a trend line whose equation is y = 3x + 10?

• A

• B

• C

• D

Tags

CCSS.8.EE.B.5

The equation of the trend line

is y hat= 1/2x +1. What does the x variable represent?

• The number of laps

• The amount of time in hours

• The amount of time in minutes

• How long it takes to go 0 laps

Tags

CCSS.HSF.LE.B.5

Sammy is selling his comic book collection on the internet. The scatterplot shows how many comic books he has left at the end of each day. Using the trend line, after how many days should Sammy predict to have 10 comic books left?

• 8

• 0

• 9

• 2

Which scatter plot could have a trend line whose equation is y hat= 3x + 10?

• A

• B

• C

• D

Tags

CCSS.HSF.LE.B.5

A small theme park is trying to determine the number of guests they should expect on a weekend, based on the temperature outside.  Based on the trend line, about how many guests should be expected if the temperature is around 80°?

• 8,300

• 8

• 7,300

• 9,300