Bell Ringer #7

Evaluate
(p/3t)/6 when p = 6 and t = 4
(2m2 + 5) – (m + 1) when m = 3
Scatter Plots and Correlation
Mr. Haupt
Scatterplots

A graph that relates two groups of data.

Plotted as ordered pairs. (x,y)

Most of the time, they are in the first quadrant
of a coordinate plane.
Example #1
Correlation

When we compare two sets of data, there
are three results.
–
–
–
Positive correlation
Negative correlation
No correlation
Positive Correlation

Positive correlation is when both sets of data
increase together.

It does not mean that one thing causes the
other, it just means that when one goes up,
so does the other.
Example #2
Negative Correlation

Negative correlation means that as one data
set increases, the other one decreases.

Again, it does not mean that one set of data
causes the other one to increase/decrease.
Example #3
No Correlation

Sometimes, data sets are not related at all.
In this case we can say there is no
correlation.

These graphs look a mess.
Example #4
I woke up like
this!
Trend Line



To show correlation more clearly, we usually
draw a trend line onto a scatter plot.
A trend line, for the most part, splits the data,
and it follows the trend that the points make.
They help us to approximate the value of one
set of data when given a value for the
second.
Example #5
So….

Go ahead and make a scatter plot from the
following data:
x
y


11
9
9
7
10
8
13
12
5
3
8
7
Draw a trend line.
Is there positive, negative, or no correlation?
4
1