8th Grade - Center For Teaching & Learningcontent.njctl.org/courses/math/8th-grade-math/data/data...6 Example 1: An ice cream shop keeps track of how much ice cream they sell versus

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8th Grade Data

20151120

www.njctl.org

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click on the topic to go to that section

Table of Contents

• Two Variable Data

• Determining the Prediction Equation

• TwoWay Table

• Line of Best Fit

• Glossary

Teacher N

otes Vocabulary Words are bolded

in the presentation. The text box the word is in is then linked to the page at the end of the presentation with the word defined on it.

4

Two Variable Data

Return toTable ofContents

5

Two Variable Data is also called

Bivariate Data

With bivariate data there are two sets of related data that you want to compare.

Two Variable Data

6

Example 1: An ice cream shop keeps track of how much ice cream they sell versus the temperature on that day.

Temperature degrees F

Ice Cream Sales $

57.5 215

61.5 325

53 185

60 332

65 406

72 522

67 412

77 614

74 541

64.5 421

This table shows 10 days of data.

The two variables are:Temperature and Ice Cream Sales.

We can create a scatter plot by plotting the points.

Temperature is the x variableSales is the y variable.

Scatter Plot

7

Ten Days of Ice Cream Shop Sales


Ice Cream

Sales $

Scatter Plot

8

What did the scatter plot show us?

Using the Scatter Plot it is easy to see that:

warmer weather leads to more sales.

Scatter Plot

click to reveal

9

Scatter Plots are either:

Linear Nonlinear

Scatter Plot

10

These scatter plot are also nonlinear.

Scatter Plot

11

If a scatter plot is linear it can be described 3 ways:Negative AssociationPositive Association

No Association

Scatter Plot

12

1 What type of scatter plot is shown from the Ice Cream Shop example 1?

A nonlinearB linear, positive association

C linear, negative associationD linear, no association


Ice Cream

Sales $

Answ

er

13

Example 2: Data for 10 students math and science grades are shown in the table. Plot the points to create the scatter plot.

Math Grade

Science Grade

56 6296 9385 8184 8263 60100 9878 8189 9146 4875 75

Math Grades

Science Grades

Scatter Plot

14

2 What type of scatter plot is shown for the math and science grades from example 2?A nonlinearB linear, positive associationC linear, negative associationD linear, no association

Math Grades

Science Grades

Click to reveal solved graph.

Answ

er

15

3 What kind of association is shown in the graph?

A nonlinear

B linear, positive associationC linear, negative association

D linear, no association

Answ

er

Time spent studying

Test Score

16

4 What kind of association is shown in the graph ?

A nonlinear

B linear, positive association C linear, negative association

D linear, no association

Shoe size & Height

shoe size

height in

inches

Answ

er

17

5 What association is

shown in this graph?

A nonlinear B linear, positive correlation C linear, negative correlation

D linear, no correlation

Answ

er

Height in inches

Weight in Po

unds

Boy's Height and Weight

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6 Which of the following scenarios would produce a linear scatter plot with a positive correlation?

A Miles driven and money spent on gas

B Number of pets and how many shoes you own C Work experience and income

D Time spent studying and number of bad grades

Answ

er

19

7 Which of the following would have no association if

plotted on a scatter plot?

A Number of toys and calories consumed in a day

B Number of books read and reading scores C Length of hair and amount of shampoo used

D Person's weight and calories consumed in a day

Answ

er

20

What kind of predictions can you make from looking at the graph?

Predictions

21

Number of Hours

Resting Heart Rate

12 616 7810 700 9016 652 854 7514 623 781 878 69

Survey Data

A student wanted to find out if there was a relationshipbetween the number of hours a person exercised in one weekand their resting heart rate. 15 people were surveyed and the table at the right shows the results.

22

Plot the results of the survey on

a scatter plot.Number of Hours

Resting Heart Rate

12 616 7810 700 9016 652 854 7514 623 781 878 69

Scatter Plot

23

Linear Relationship? Association?

Is there a linear relationship?

Is there a positive or negative association?

According to your scatter plot, does a person who exercise generally have a lower resting heart rate than a person that doesn't exercise?

24

Hours Math Grade

2 967 754 861 940.5 978 702 903 8710 681 946 754 88

Sandy wanted to find out if there was a relationship between the number of hours a student spent browsing the Internet ineach day and their math grades for the marking period.She surveyed several students and the results are shownin the table at the right.

Survey Data

25

Look at your results. Is the scatter plot linear or nonlinear? Is there a positive or negative association?What can you say about the math scores as more hours are spent browsing the Internet?


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YearTemperatur

e in F

2,000 30.42,001 30.12,002 37.32,003 26.72,004 24.82,005 30.32,006 38.92,007 37.12,008 34.52,009 27.32,010 31.4

The table shows average temperatures for the month of January in New Jersey from 2000 to 2009.

Is it linear?Is there a positive association,negative association, or neither?


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MonthTemperatur

e in F

1 35.42 38.83 49.84 52.85 65.36 70.27 78.28 759 6710 5711 4912 40.8

The table shows average temperature by month for New Jersey. Month 1 = January, Month 2 = February, etc.Make a scatter plot using the data from the table.Is the graph linear? Is there an association?


Answ

er

28

Shoe Size v. Girl's Height

Shoe Size

Heigh

t in Inches

8 What association is shown in this graph?A nonlinear B linear, positive association

C linear, negative association D linear, no association

Shoe Size

Girl's Height in Inches

5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66

Answ

er

29

Poll 10 girls and 10 boys from your class on their heights and shoe size. Make a scatter plot for your observations.

Girls Height (in inches)

Shoe Size

Boys Height (in inches)

Shoe Size

Poll

Teacher N

otes

30

Wake Up Time

How Long to Get Ready

Survey your classmates and to find out what time they wake up on a school day and how long it takes them to get ready. Make a scatter plot of your results.

Is there an association with the time a student wakes up and how long it takes them to get ready?

Survey

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Line of Best Fit


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Line of Best Fit

Bivariate data plotted on a scatter plot shows us negative or positive association (correlation).

A line of best fit, or trend line, can help us predict outcomes using the data that you already have.It is drawn on a scatter plot that best fits the data points.

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Line of Best Fit

Notice that the points form a linear like pattern. To draw a line of best fit, use two points so that the line is as close as possible to the data points.

Our line is drawn so that it fits as close as possible to the data points. This line was drawn through (35,82) and (50,90).

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Time spent studying

Test Score

Line of Best Fit

Predict the test score of someone who spends 52 minutes studying.Predict the test score of someone who spends 75 minutes studying.

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Shoe size & Heightheight in inches

shoe size

Draw a line of best fit, or trend line, on this graph.

Predict the height of a person who wears a size 8 shoe.Predict the shoe size of a person who is 50 inches tall.

Line of Best Fit

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9 Consider the scatter graph to answer the following: Which 2 points would give the best line of fit?

X Y3 9

4.5 8

5 76 58 49 310 1

B

CD

A

A A and D

B B and C

C C and D

D there is nopattern

Answ

er

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10 Consider the scatter graph to answer the following: Which 2 points would give the best line of fit?

X Y5 26 47 38 4

9 4.5

9 510 3

A

CB D

A A and D B B and C C C and D D there is no

pattern

Answ

er

38

11 Which two points would you pick to draw

the line of best fit?

D

X Y

2 96

7 75

4 86

1 94

0.5 97

8 70

2 90

3 87

10 68

1 94

6 75

4 88

B

C

AA A and B B B and C C C and D D A and D

Answ

er

39

Shoe Size

Girl's Height in

Inches5 555.5 548 647.5 659 706 527.5 638 66


Shoe SizeHeigh

t in Inches

A

B

C

D

12 Which two points

would you use to

draw the line of

best fit?

A A and D B C and D C B and D

Answ

er

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13 A scatter plot is shown on the coordinate plane.

Which of these most closely approximates the line of best fit for the data in the scatter plot?

A

B

C

D

From PARCC EOY sample test noncalculator #15

Answ

er

http://practice.parcc.testnav.com/#

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Line of Best Fit

Using the scatter plot you created for shoe size v. girls' heights and shoe size v. boys' heights, determine line of best fit that goes through each of these scatter plots.

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Determining the Prediction Equation


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Line of Best FitThe points form a linear like pattern, so use two of the points to draw a line of best fit.

Our line is drawn so that it fits as close as possible to the data points. This line was drawn through (35,82) and (50,90).

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Use the two points that formed the line to write an equation for the line.

Find m Find b

Prediction Equation

This equation is called the Prediction Equation.The slope also shows that a student's score will increase by 8 for every 15 minutes of studying they do.

Where S is the score for t minutes of studying.

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Prediction Equations can be used to predict other related values.

If a person studies 15 minutes, what would be the predicted score?

This is an extrapolation, because the time was outside the range of the original times.

Prediction Equation

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If a person studies 42 minutes, what would be the predicted score?

This is an interpolation, because the time was inside the range of the original times.

Prediction Equation

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Interpolations are more accurate because they are within the set.

The farther points are away from the data set the less reliable the prediction.

Using the same prediction equation, consider:

If a person studies 120 minutes, what will be their score?

What is wrong with this prediction?

Prediction Equation

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If a student got an 80 on the test, What would be the predicted length of their study time?

The student studied about 31 minutes.

Prediction Equation

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14 Consider the scatter graph to answer the following: What is the slope of the line of best fit going through A and D?

X Y3 95 76 58 49 310 1

A

D(9, 3)

(3, 9)A

B

C D

Answ

er

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15 Consider the scatter graph to answer the following: What is the yintercept of the line of best fit going through A and D?

X Y3 94.5 8

5 76 58 49 310 1

A

D

(9, 3)

(3, 9)A 9

B 10

C 11

D 12

Answ

er

51

16 Consider the scatter graph to answer the following: The equation for our line is y = 1x + 12. What would the prediction be if x = 7? Is this an interpolation or extrapolation?

X Y3 94.5 8

5 76 58 49 310 1

A

D

A 5, interpolation

B 5, extrapolation

C 6, interpolation

D 6, extrapolation

Answ

er

52


X Y3 94.5 8

5 76 58 49 310 1

A

D

A 4, interpolation

B 4, extrapolation

C 2, interpolation

D 2, extrapolation

Answ

er

53


X Y3 9

4.5 8

5 76 58 49 310 1

A

D

A 1, interpolation

B 1, extrapolation

C 2, interpolation

D 2, extrapolation

Answ

er

54

19 In the previous questions, we began by using the table at the right. Which of the predicted values: (7,5) or (14, 2) will be more accurate and why?

A

B

C

D

X Y3 9

4.5 8

5 76 58 49 310 1

(7,5); it is an interpolation.

(7,5); there already is a 5 and a 7 in the table

(14, 2) it is an extrapolation

(14, 2); the line is going down and will become negative

Answ

er

55

20 What is the slope of this best

fit line that goes through

A and C?

A

B

C

D

X Y3 62 55 94 81 36 107 129 14

C

A

Answ

er

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21 What is the yintercept of

the line of best fit that goes

through A and C?

A

B

C

D

C

A

X Y3 62 55 94 81 36 107 129 14

Answ

er

57

X Y3 6

2 5

5 9

4 8

1 3

6 10

7 12

9 14

22 The equation for the line of best fit

is . What would the prediction be if

y = 4.5? Is this an interpolation or

extrapolation?

A 8, interpolation

B 8, extrapolation

C 6.5, interpolation

D 6.5, extrapolation

Answ

er

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X Y3 6

2 5

5 9

4 8

1 3

6 10

7 12

9 14

23 The equation for the line of best fit

is . What would the prediction be if

y = 8? Is this an interpolation or

extrapolation?

A

B

C

D

interpolationextrapolation

interpolation

extrapolation

Answ

er

59

Shoe Size

Girl's Height in

Inches5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66


Shoe Size

Heigh

t in Inches

Prediction EquationCalculate the prediction equation using the two labeled points.

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Shoe Size

Girl's Height in

Inches5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66


Shoe Size

Heigh

t in Inches

24 What is the slope of the

prediction equation

for this graph?

Answ

er

61

Shoe Size

Girl's Height in

Inches5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66


Shoe Size

Heigh

t in Inches

25 A girl with a size 7 shoe

and height of 56 inches

will be an interpolation.

True

False

Answ

er

62

Shoe Size

Girl's Height in

Inches5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66


Shoe Size

Heigh

t in Inches



will be an interpolation.

True

False

Answ

er

63

Shoe Size

Girl's Height in

Inches5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66


Shoe Size

Heigh

t in Inches

27 What will the height be

of a girl with a size

8.5?

Answ

er

64

Shoe Size

Girl's Height in

Inches5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66


Shoe Size

Heigh

t in Inches



will be an extrapolation.

True

False

Answ

er

65

Shoe Size

Girl's Height in

Inches5 55

5.5 54

8 64

7.5 65

9 70

6 52

7.5 63

8 66


Shoe Size

Heigh

t in Inches

29 Using the prediction

equation, what will the

height be of a girl

who has a size

10 shoe?

Answ

er

66

Prediction Equation

Using the scatter plot you created for the shoe size v. girls' heights and shoe size v. boys' heights from your class, determine the prediction equation for each graph.

Using the equation, how tall is a girl that wears a 9.5 size shoe?

How tall is a boy that wears a 6.5 shoe?

67

TwoWay Tables


68

Take a Bicycle to School

Do Not Take a Bicycle to School Total

Take the Bus to School 5 7 12

Do Not Take the Bus

to School6 12 18

Total 11 19 30

TwoWay TablesWe can also organize data gathered in a twoway table.

Twoway tables display information as it pertainsto two different categories.

Here is an example of a twoway table:

69

TwoWay Tables

What does the twoway table show us?

The table below shows information gathered from 30 students. They were asked if they took a bus or a bicycle to school.




Do Not Take the Bus

to School6 12 18

Total 11 19 30

70




Do Not Take the Bus

to School6 12 18

Total 11 19 30

As you can see from the table, some students take the bus,other students ride their bicycles, take the bus or ride a bicycle to school. Several students do not take a bus nor ride their bicycles to school.

TwoWay Tables

Let's answer some questions using the data from the table.

71

30 From this table, how many students take the bus

or ride their bicycle to school?




Do Not Take the Bus

to School6 12 18

Total 11 19 30

Answ

er

72

31 How many students take the bus, but do not

ride their bicycles to school?




Do Not Take the Bus

to School6 12 18

Total 11 19 30

Answ

er

73

32 How many students do not take the bus to school?




Do Not Take the Bus

to School6 12 18

Total 11 19 30

Answ

er

74

33 How many students ride their bicycles to school,

but do not take the bus?




Do Not Take the Bus

to School6 12 18

Total 11 19 30

Answ

er

75

Henry surveyed students from several classes to find out if they did chores and received an allowance. 65 students did chores. Of those 65 students, 49 received an allowance. There were 26 students that did not do chores and did not receive an allowance. 10 students that did not do chores, but received an allowance.

Set up your table, and label the categories.

Allowance No Allowance Total

Chores

No ChoresTotal

TwoWay Tables

76

TwoWay Tables


Chores 65

No ChoresTotal

65 students did chores. Where would you write that number?

Notice that the "Chores" and "No Chores" categories are in the rows, and the "Allowance" and "No Allowance" categories are in the columns.

77

TwoWay Tables


Chores 49 65

No ChoresTotal

Of those 65 students, 49 received an allowance. Where would you write the 49?

Look at the "Chores" category, then "Allowance" since the 49 students who did chores received an allowance.

78

TwoWay Tables


Chores 49 65

No Chores 26Total

There were 26 students that did not do chores and did not receive an allowance.

Look at the "No Chores" category and "No Allowance" category.

79

TwoWay Tables


Chores 49 65

No Chores 10 26Total

10 students that did not do chores, but received an allowance.

Look for the "No Chores" category then "Allowance" category.

80


Chores 49 65 49 = 16 65No Chores 10 26 10 + 26 = 36

Total 49 + 10 = 59 16 + 26 = 4265 + 36 = 101 or

59 + 42= 101

If you did your math correctly, the total row and column should be the same.

TwoWay TablesThis is the table filled using the information that was given. Although some of the cells are not filled, you can easily find the rest of the information with simple math.

81


Chores 49 16 65No Chores 10 26 36

Total 59 42 101

TwoWay Tables

Here is the final table. Now you can answer some questions using the data.

82

34 How many students took this survey?



Total 59 42 101

Answ

er

83

35 How many students do chores, but do not receive an allowance?



Total 59 42 101

Answ

er

84

36 How many students do not do chores, but still receive an allowance?



Total 59 42 101

Answ

er

85

Laptop Computer

No Laptop Computer Total

Desktop ComputerNo Desktop Computer

Total

Survey your class to find out if each student has a laptop computer and/or desktop computer at home.

Make a twoway table showing your results.

TwoWay Tables

86

Relative Frequency

Using twoway tables, we can calculate relative frequencies.

Relative frequencies are ratios that compares the value of a certain category to the subtotal in that category.

As you have previously learned, the frequency is the quantity of just how many of a certain event occurs.Relative frequency is how many compared to the subtotal. The relative frequency is written as a fraction or decimal.

87

Relative Frequency

Example: There are 12 girls in a class of 20 students.The frequency of number of girls in a class is 12.The relative frequency of the number of girls in the class is or 0.60.

What is the frequency of girls in your class? What is the relative frequency?

What is the frequency of boys in your class? What is the relative frequency?

88




Do Not Take the Bus

to School6 12 18

Total 11 19 30

Relative Frequency

Calculate the relative frequency for the twoway table from earlier by row and then by column.

89



Take the Bus to School

0.42 + 0.58 = 1.00

Do Not Take the Bus

to School

0.33 + 0.67 = 1.00

Total0.37 + 0.63 = 1.00

For this cell, the relative frequency of students taking a bicycle to school or the bus to school is divided by the total number of students that take the bus to school.

Relative Frequency

By row:

90




Do Not Take the Bus

to School

Total 1.00 1.00 1.00

For relative frequency by column, the number of students that take a bicycle to school or take a bus to school is divided by the number of students that take a bicycle to school.

Relative Frequency

By column:

91




0.42 + 0.58 = 1.00

Do Not Take the Bus

to School

0.33 + 0.67 = 1.00

Total0.37 + 0.63 = 1.00

Let's answer some questions using the relative frequencies.

By row:

What is the relative frequency of students that take a bicycle to school and also take a bus to all students taking a bus to school?

Relative Frequency

Answer

92




0.42 + 0.58 = 1.00

Do Not Take the Bus

to School

0.33 + 0.67 = 1.00

Total0.37 + 0.63 = 1.00

By row:

What is the relative frequency of students that do not take a bicycle to school and do not take a bus to all students that do not take a bus to school?

Relative Frequency

Answer

93




0.42 + 0.58 = 1.00

Do Not Take the Bus

to School

0.33 + 0.67 = 1.00

Total0.37 + 0.63 = 1.00

By row:

37 What is the relative frequency of students that take a bicycle to school but do not take a bus to the total number of students that do not take the bus?

Answ

er

94




0.42 + 0.58 = 1.00

Do Not Take the Bus

to School

0.33 + 0.67 = 1.00

Total0.37 + 0.63 = 1.00

By row:

38 What is the relative frequency of the students that do not take a bicycle to school, but do take the bus to the all the students that take the bus to school?

Answ

er

95

39 By Column:What is the relative frequency of students that take a bicycle to school and also take a bus to school, to the total number of students that take a bicycle to school?

By column: Take a Bicycle to School



Do Not Take the Bus

to School

Total 1.00 1.00 1.00

Answ

er

96




Do Not Take the Bus

to School

Total 1.00 1.00 1.00

40 What is the relative frequency of students that do not take a bicycle to school and do not take the school bus to the total number of students that do not take a bicycle to school?

Answ

er

97




Do Not Take the Bus

to School

Total 1.00 1.00 1.00

41 What is the relative frequency of students that take a bicycle to school, but do not take the bus to all students that take a bicycle to school?

Answ

er

98



Total 59 42 101

Use the following twoway table to calculate the relative frequencies by row.

Relative Frequency By Row


Chores

No ChoresTotal

99


Chores 1.00

No Chores 1.00

Total 1.00

For example, does there seem to be a relationship between whether or not a student receives an allowance compared to whether or not a student does chores?

By row:

Why do we calculate relative frequencies? We can use relative frequencies to determine if there is an association between the two categories.

Relative Frequency

Approximately 0.75 or 75% of students that receive an allowance do chores, and out of those that do chores only 0.25 or 25% of students receive no allowance.

100



Total 59 42 101

Use the following twoway table to calculate the relative frequencies by column.

Relative Frequency By Column


Chores

No ChoresTotal

Is there a relationship between students that do chores to the amount of students that receive an allowance?

101

Cat No Cat TotalDog

No DogTotal

Construct a twoway table using the following information.

Kelly found that 49 people had dogs in her school. Out of the 49 people, 30 people had cats. 50 people had cats in her school.22 people had neither cats nor dogs at home.

Twoway Table

102

Cat No Cat TotalDog

No DogTotal

Cat No Cat TotalDog

No DogTotal

By row:

By column:

Relative Frequency

Using the twoway table, calculate the relative frequencies by column and by row.

103

Cat No Cat TotalDog

No DogTotal

42 What is the relative frequency of the people who have a cat and a dog at home to the number of people that have cats?

Cat No Cat TotalDog 30 19 49

No Dog 20 22 42

Total 50 41 91

Answ

er

104

Cat No Cat TotalDog

No DogTotal

43 What is the relative frequency of the people who have a dog and a cat to the number of people that have a dog?

Answ

er

105

Cat No Cat TotalDog

No DogTotal

44 What is the relative frequency of the people who have no cat, but have a dog to the number of people that have no cats?

Answ

er

106

45 The table shows the results of a random survey of students in grade 7 and grade 8. Every student surveyed gave a response. Each student was asked if he or she exercised less than 5 hours last week or 5 or more hours last week. Based on the results of the survey, which statements are true? Select each correct statement.

A More grade 8 students were surveyed than grade 7 students.

B A total of 221 students were surveyed.

C Less than 50% of the grade 8 students surveyed exercised 5 or more hours last week.

D More than 50% of the students surveyed exercised less than 5 hours last week.

E A total of 107 grade 7 students were surveyed.

From PARCC EOY sample test calculator #3

Answer

http://practice.parcc.testnav.com/#

107

Survey your classmates to find out if they play sports and/or play an instrument. Construct a twoway table displaying the results. (Write "yes" or "no") Then calculate the relative frequencies by row and by column.

Is there a relationship between the number of students that play sports vs. the number of students that play an instrument?

Construct a Twoway Table

108

Glossary


Teacher N

otes Vocabulary Words are bolded

in the presentation. The text box the word is in is then linked to the page at the end of the presentation with the word defined on it.

109

Back to Instruction

Bivariate DataTwo sets of related data that is being compared. Data of two variables.

(TwoVariable Data)

Variables:1. Temperature 2. Sales

Variables:1. Shoe Size

Variables:1. Hours 2. Math Grade

Bivariate Data

1 variable

Univariate Data

110

Back to Instruction

(53,180)

(77,610)

range =

610 180

If it is 50o outside, what would

be the predicted ice cream sales? y = 17x 721 y = 17(50) 721 y = 851 721 y = 129

$129

$129 < $180


be the predicted ice cream sales?

y = 17x 721 y = 17(90) 721 y = 1,530 721 y = 809

$809

$809 > $610

Extrapolation

A data point that is outside the range of data.

111

Back to Instruction

FrequencyThe quantity of just how many of a

certain even occurs.

The frequency of

kids who do not take

the bus to

school is 18.

The frequency of

kids who take the

bus to school is 12.

The frequency of

kids who ride their

bikes to school is 11.

112

Back to Instruction



y = 17x 721 y = 17(70) 721 y = 1,190 721 y = 469

$469

$180 < $469 < $610



$350

$180 < $350 < $610

y = 17x 721 y = 17(63) 721 y = 1,071 721 y = 350

Interpolation

A data point that is inside the range of data.

(53,180)

(77,610)

range =

$610

$180

113

Back to Instruction

Linear

A graph that is represented by a straight line.

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Line of Best FitA line on a graph showing the general

direction that a group of points seem to be heading. Trend Line.

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Negative Association

A correlation of points that is linear with a negative slope.

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No Association

A correlation of points that is linear with a slope of zero. A horizontal line graph.

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NonLinear

A graph that is not represented by a straight line. A curved line.

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Positive Association

A correlation of points that is linear with a positive slope.

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y = mx+b

y = 17x 721 (53,180)

(73,520)

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Prediction Equation


Ice Cream

Sales $

If it is 70o outside, what would be the predicted ice cream sales?

y = 17x 721 y = 17(70) 721 y = 1,190 721 y = 469

$469

An equation that is created using the line of best fit. A line that can predict

outcomes using the given data.

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Relative Frequency

The relative frequency of

students who only take the bus to

the total bus riders is

0.58.


students who only ride their bikes to the total bike riders is 0.33.


students who only ride their bikes to the total students

is 0.37.

Ratios that compares the value of a certain category to the subtotal in that category.

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A graph of plotted points that show the relationship between two sets of data.

Scatter Plot

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TwoWay Table

A table that displays information as it pertains to two different categories.

School Bus vs. Bicycle

Allowance vs. Chores

Documents

8th Grade - Center For Teaching & Learningcontent.njctl.org/courses/math/8th-grade-math/data/data...6 Example 1: An ice cream shop keeps track of how much ice cream they sell versus