presentation of data - how to construct graphs

Prepared by:

MS. MA. IRENE G. GONZALES

Mathematics Department

University of Santo Tomas Junior High School

How far can you remember?

COP + describing

predictions

totality

subset

values in between

descriptive attributes

How far can you remember?

COPAI

Direct method

Use of senses

How far can you remember?

laws

Indirect method

Previously recorded data

How far can you remember?

Equal chance of being selected

Every nth element

Groups or clusters

How far can you remember?

Groups of the same interest

Visual form

Paragraph form

How far can you remember?

Looking back…

• Differentiated the three ways of

presenting data

• Analyzed the different graphs

– Line Graph

– Bar Graph

– Circle Graph

GOALS

• Identify the proper ways/steps of

constructing graphs

• Use graphs appropriately to represent

organized data

Somewhere over the

rainbowJust Right Over my dead body

Right under the nose Looking out for

number one

Home is where the

heart is

Consider the data below:

Day Chocolate Strawberry White

Monday 53 78 126

Tuesday 72 97 87

Wednesday 112 73 86

Thursday 33 78 143

Friday 76 47 162

The cafeteria wanted to collect data on howmuch mL of milk was sold in 1 week. The tablebelow shows the results:

Bar Graph

A bar graph is usedto showrelationshipsbetween groups.

The two or moreitems beingcompared do notneed to affect eachother.

Mon Tue Wed Thu Fri Total

53 72 112 33 76 346

53

72

112

33

76

0

20

40

60

80

100

120

Monday Tuesday Wednesday Thursday Friday

Day

Chocolate Milk Sold

Am

ou

nt

of

Mil

k S

old

in

mL

0 20 40 60 80 100 120 140 160 180

Monday

Tuesday

Wednesday

Thursday

Friday

White

Strawberry

Chocolate

Examine the graph

How to Construct a Bar Graph

• Give the title of the bar

graph;

• Decide if a vertical or a

horizontal bar graph will

be used;

• Draw the horizontal and

vertical axes;

• Determine the scale

interval on the axes and

then label the graph;

• Draw bars with the same

width and space them

evenly on one axis.

53

72

112

33

76

0

20

40

60

80

100

120

Monday Tuesday Wednesday Thursday Friday

Day

Chocolate Milk Sold

Am

ou

nt

of

Mil

k S

old

in

mL

Do this on your notebook!

• Give the title of the bar

graph;

• Decide if a vertical or a

horizontal bar graph will

be used;

• Draw the horizontal and

vertical axes;

• Determine the scale

interval on the axes and

then label the graph;

• Draw bars with the same

width and space them

evenly on one axis.

Preferred snacks of students

during recess

Type of

Snacks

No. of

Students

Spaghetti 12

French

Fries

15

Biscuits 6

Donut 9

Line Graph• A line graph is used to show

continuing data; how one thing is affected by another.

• Shows the relationship between continuous data

0

20

40

60

80

100

120

Monday Tuesday Wednesday Thursday FridayDay

Chocolate Milk Sold

Mon Tue Wed Thu Fri Total

53 72 112 33 76 346

Am

ou

nt

of

Mil

k S

old

in

mL

10 11

1618 17

20

0

5

10

15

20

25

Yr 1 Yr 2 Yr 3 Yr 4 Yr 5 Yr 6

Annual Sales of Gonzales’ Corporation from Yr 1 to Yr

6

Annual S

ale

s in M

illio

ns

Year

How to Construct a Line Graph• Give the title of the

line graph;

• Draw the horizontal

and vertical axes;

• Determine the scale

interval on the axes

and then label the

graph;

• Plot a point to

represent each entry

in the data;

• Connect the

successive points

using line segments

Do this on your notebook!

Draw the line graph for the following data

which shows the changes in temperature

(in degree Celcius) for 4 days in Quezon

City:

Monday – 25 degree Celcius

Tuesday – 30 degree Celcius

Wednesday – 32 degree Celcius

Thursday – 35 degree Celcius

Circle Graph or Pie Graph

• A circle graph is used to show how a part of something relates to the whole.

• This kind of graph is needed to show percentages effectively.

15%

21%

32%

10%

22%

Chocolate Milk Sold

Monday

Tuesday

Wednesday

Thursday

Friday

Mon Tue Wed Thu Fri Total

53 72 112 33 76 346

How to Construct a Circle Graph

• To compute for the angle of each sector by using the formula:

• To convert each frequency to a percentage use the formula:

degrees =frequency

totalx360°

percentage =frequency

totalx100%

Let’s see HOW you DO it…

Construct a pie graph given the tabular data

on the population of students enrolled in

USTJHS for the A.Y. 2015 - 2016

G7 G8 G9 G10

350 385 420 405

Choosing the Right Graph

Use a pie chart if you need to compare differentparts of a whole, there is no time involved andthere are not too many items (or categories).

Use a line graph if you need to see how aquantity has changed over time. Line graphsenable us to find trends (or patterns) over time.

Use a bar graph if you are not looking for trends(or patterns) over time; and the items (orcategories) are not parts of a whole.

The allocation of the monthly budget of a family

CONCEPTUAL CHECK

Which statistical graph best fit for the set of data?

ANSWER: Circle or Pie Chart

The donations by each grade level of UST High School for the victims of

Typhoon Yolanda

ANSWER: Bar Graph

CONCEPTUAL CHECK

Which statistical graph best fit for the set of data?

Changes in temperature over a week in Manila

ANSWER: Line Graph

Which statistical graph best fit for the set of data?

CONCEPTUAL CHECK

The number of members per grade level for the Math Club for

S.Y. 2014 – 2015

ANSWER: Circle or Pie Chart

CONCEPTUAL CHECK

Which statistical graph best fit for the set of data?