1Lesson 11.4: Scatter Plots Standards: M7D1f & M7A3a & c Objective: To construct a scatter plot and determine the relationship between two variables.
2Scatter PlotA scatter plot is a graph of plotted points that shows if there is a relationship between two sets of data or two variables.The graph looks like a bunch of dots, but some of the graphs have a general shape or move in a general direction.
3This vertical line is called the y-axis. THE COORDINATE PLANEyThis vertical line is called the y-axis.
4This horizontal line is called the x-axis. THE COORDINATE PLANEy54321-1-2-3-4-5This horizontal line is called the x-axis.x-5-4-3-2-112345
5The x-axis and y-axis separate the coordinate plane into 4 parts. 54321-1-2-3-4-5The x-axis and y-axis separate the coordinate plane into 4 parts.x-5-4-3-2-112345This point in the middle of the x-axis and y-axis is called the origin.
6These parts are called Quadrants. THE COORDINATE PLANEy54321-1-2-3-4-5Quadrant IIQuadrant IThese parts are called Quadrants.x-5-4-3-2-112345Quadrant IIIQuadrant IV
7y x THE COORDINATE PLANE ( 1 , 3 ) 54321-1-2-3-4-5To locate a point anywhere on the grid, you need an ordered pair.An ordered pair is a pair of numbers used to locate points on a grid.x-5-4-3-2-112345The FIRST number is called the X- coordinate.( 1 , 3 )The SECOND number is called the Y- coordinate.
8Ordered pair to graph (x, y) Construct a scatter plot to show the relationship between the hours spent practicing shooting darts and the dart shooting score.Practice Time (hours)Dart Shooting ScoreOrdered pair to graph (x, y)16(1, 6)28(2, 8)313(3, 13)420(4, 20)518(5, 18)27(6, 27)
9Ordered pair to graph (x, y) Construct a scatter plot to show the relationship between the hours spent practicing shooting darts and the dart shooting score.Practice Time versusDart Shooting Time30Ordered pair to graph (x, y)(1, 6)(2, 8)(3, 13)(4, 20)(5, 18)(6, 27)2520Dart Shooting Score15105123456Practice Time (hrs)
10Positive CorrelationIf the x-coordinates and the y-coordinates both increase, then the two variables are said to have a POSITIVE CORRELATION.This means that both are going up, and they are related.
11Positive CorrelationIf you look at the age of a child and the child’s height, you will find that as the child gets older, the child gets taller. Because both are going up, it is positive correlation.Can you think of any other examples ofvariables with a positive relationship?Age12345678Height “2531343640414755
12Negative CorrelationIf the x-coordinates and the y-coordinates have one increasing and one decreasing, then the two variables are said to have a NEGATIVE CORRELATION.This means that 1 is going up and 1 is going down, making a downhill graph. This means the two are related as opposites.
13Negative CorrelationIf you look at the age of your family’s car and its value, you will find as the car gets older, the car is worth less. This is negative correlation.Can you think of anything else witha negative relationship?Age of car12345Value$30,000$27,000$23,500$18,700$15,350
14No CorrelationIf there seems to be no pattern, and the points looked scattered, then it is no correlation.This means the two are not related.
15No CorrelationIf you look at the size shoe a baseball player wears, and their batting average, you will find that the shoe size does not make the player better or worse, then are not related.
16Which scatterplots below show a linear trend? NegativeCorrelationPositiveCorrelationb)d)f)ConstantCorrelation
17Objective - To plot data points in the coordinate plane and interpret scatter plots. ySport Utility Vehicles(SUVs) Sales in U.S.54321YearSales (in Millions)19910.919921.1Vehicle Sales (Millions)19931.419941.619951.719962.119972.419982.7x19993.2Year
18Scatterplot - a coordinate graph of data points. yTrend appears linear.54321Trend is increasing.Vehicle Sales (Millions)Positive correlation.Predict the sales in 2001.xYear
19Plot the data on the graph such that homework time is on the y-axis and TV time is on the x-axis..Time SpentWatching TVTime Spenton HomeworkStudentSam30 min.180 min.Jon45 min.150 min.Lara120 min.90 min.Darren240 min.30 min.Megan90 min.90 min.Pia150 min.90 min.Crystal180 min.90 min.
20Plot the data on the graph such that homework time is on the y-axis and TV time is on the x-axis.TVHomework24021018015012090603030 min.180 min.45 min.150 min.120 min.90 min.HomeworkTime on240 min.30 min.90 min.120 min.150 min.120 min.180 min.90 min.Time Watching TV
21Describe the relationship between time spent on homework and time spent watching TV.Trend appears linear.240210180150120906030Trend is decreasing.HomeworkTime onNegative correlation.Time Watching TV