1. Draw a line with a positive slope. How can you tell when a line has a positive slope? 1. Draw a line with a negative slope. How can you tell when a line has a negative slope. 1. Describe, in words, how you would plot the points (2, -5) and (-3, 7).
SWBAT identify and interpret positive, negative, and no correlation and strong vs. weak correlations on a graph. SWBAT draw scatterplots by hand and using the calculator. SWBAT describe the relationship between an independent and dependent variable based on the scatter plot shown.
A graph of plotted points that show the relationship between two sets of data They tell us if the two different variables are related, and if so, HOW they are related.
In the news. In science class. Where else can you think of?
then you can determine if a scatter plot is showing a positive or negative relationship between variables! POSITIVE (the dots are going up) NEGATIVE (the dots are going down)
Which we call NO CORRELATION
Correlation means relationship. When we say something has a positive correlation, it has a positive relationship. A negative correlation, means negative relationship. No correlation means that there is no relationship between the two variables.
We can also describe correlations as: strong or weak
Draw three scatterplots using any combination of positive, negative, or no correlation AND strong or weak.
Walk around the room, high-fiving your classmates. When I say “pair up,” the person that you are high-fiving becomes your partner. Exchange scatterplots with your new partner. Describe the correlations of your partners’ scatterplots and check to see if you agree.
Again, correlation means RELATIONSHIP. But correlation does not mean that one variable causes the other. For example, there may be a relationship between age and weight, but being older does not necessarily cause you to weigh more. Can you think of another example?
What type of correlation do we see here? So, that means that your height as an adult depends on how tall you were when you were born. Since they are positively correlated, this graph tells us that the taller you are at birth, the taller you will be when you are a fully grown adult. Infant Birth Height Height as an Adult What does the scatter plot above tell us about the relationship between infant birth height and your height as an adult?
Average Neighborhood Income Crime Rate
What does the scatter plot above tell us about the relationship your English grade and the # of M&Ms you eat? Number of M & Ms you eat Your Grade in English
Hours spent studying Grade earned on test Is it positive, negative, or no correlation? Strong or weak? What does this mean about the relationship between hours spent studying and grades?
First, label your axes with the given variables. Then label the axes in even increments so that your data will fit on the graph. What are even increments? How do you know if you have chosen good increments? Then plot your points.
XY
WeekAverage Temperature
Height (inches)Weight (lbs)
Here’s how: STAT EDIT Type the values for the first variable (x) in L1 Type the values for the second variable (y) in L2 2 nd Y= ENTER ON ZOOM 9: STAT
XY
WeekAverage Temperature
Height (inches)Weight (lbs)
In order to actually use scatter plots to help them figure out things about real life data, economists and business people figure out the actual equation of the line that matches their scatter plot. This is called a trend line or a line of best fit.
We will use our calculators to get the exact line of best fit tomorrow. For now, we will draw them by hand.
XY
WeekAverage Temperature
Height (inches)Weight (lbs)
You may use your notes, but not your neighbors. I want to see what YOU know! Put it in the box when you are finished and return to your seat.
Workbook p. 163 (1, 2), p. 164 (11-15)