Slide 1

Exploring Relationships Between Numerical Variables Scatterplots

Slide 2

Seating Chart

Slide 3

Try this The first step in analyzing data it to make a ______. What is the slope of the following line? graph

Slide 4

Vocabulary A __________ helps us decide if there is a relationship between two numerical variables. The __________ variable is plotted on the x-axis. The ________ variable (the one we are most interested in) is plotted on the y-axis. scatterplot explanatory response

Slide 5

Golf The goal of golf is to putt at or under ___. Every round starts off at the_______. The golfer must decide: Hit ____(use a driver & hit off a tee) Hit ______(fairway has short grass) Very difficult to be accurate when hitting __. Does the average driving distance affect accuracy? par tee box long straight far

Slide 6

Making a Scatterplot (by hand) Decide which variable is the explanatory variable and label the x-axis. Label the y-axis with the response variable. Scale each axis individually. Draw a dot to represent each athlete. Average Driving Distance Driving Accuracy 245 250 255 260 265 270 275 0.64 0.68 0.72 0.76 0.80 0.84 0.88

Slide 7

Making a Scatterplot (TI-84) Enter L 1 (explanatory variable / x-axis) Enter L 2 (response variable / y-axis) Turn the Scatterplot on

Slide 8

Making a Scatterplot (TI-84) Look at the scatterplot Check out the scale

Slide 9

Association: direction There exists a relationship between the two variables. Negative Positive

Slide 10

Association: no direction If there is no relationship between the two variables, we say there is __ association. no Mean Driving Accuracy Mean Putting Average Good Drivers Bad Putters Good Drivers Bad Putters Bad Drivers Bad Putters Bad Drivers Bad Putters Bad Drivers Good Putters Bad Drivers Good Putters Good Drivers Good Putters Good Drivers Good Putters

Slide 11

Association: form Linear Non-Linear

Slide 12

Association: strength Very Strong Strong Moderate Weak

Slide 13

Sum it Up The _________ is a graph that displays the relationship between two numerical variables. In a scatterplot, the __________ variable is plotted on the horizontal axis and the ________ variable is plotted on the vertical axis. We can describe the __________ of two variables: direction (________ or _______ ) form ( _____ or_________ ) strength (_____ to ____ ) scatterplot explanatory response association positive negative linear non-linear strong weak