Unit 16Data Presentation

Pie Charts

Here is table of time spent by a student on homework one evening

Represent the data with a pie chart

Subject Maths English Physics Art French History

Time (mins) 50 20 30 20 30 30

Subject Time Fraction of total time Angle

Maths 50

English 20

Physics 30

Art 20

French 30

History 30

TOTAL 180

Here is a table of time spent by a student on homework one evening

Subject Maths English Physics Art French History

Time (mins) 50 20 30 20 30 30

Angle 100◦ 40◦ 60◦ 40◦ 60◦ 60◦

MathsMaths

EnglishEnglish

PhysicsPhysics

ArtArt

FrenchFrench

HistoryHistory

Unit 16Data Presentation

Line Graphs

Samuel recorded the temperature in his greenhouse at 6am each day for a week. His records are shown on this line graph.

a)What was the temperature on Wednesday?

b)What was the lowest temperature recorded?

c)What was the highest temperature recorded?

25oc25oc

19oc19oc

30oc30oc

Unit 16Data Presentation

Histograms

A group of students measured the reaction times of 50 other students. The times are given below correct to the nearest hundredth of a second.

Collect data into groups, using a tally chart.

0.44 0.32 0.31 0.47 0.27 0.31 0.40 0.28 0.16 0.26

0.33 0.46 0.41 0.33 0.31 0.28 0.38 0.29 0.17 0.26

0.29 0.40 0.29 0.24 0.41 0.22 0.25 0.47 0.31 0.36

0.49 0.21 0.42 0.43 0.28 0.36 0.24 0.37 0.43 0.27

0.49 0.16 0.29 0.30 0.41 0.27 0.29 0.28 0.40 0.42

Reaction Time (s) Tally Frequency

0.15 ≤ t < 0.20

0.20 ≤ t < 0.25

0.25 ≤ t < 0.30

0.30 ≤ t < 0.35

0.35 ≤ t < 0.40

0.40 ≤ t < 0.45

0.45 ≤ t < 0.50

Collect data into groups, using a tally chart.

Reaction Time (s) Tally Frequency

0.15 ≤ t < 0.20

0.20 ≤ t < 0.25

0.25 ≤ t < 0.30

0.30 ≤ t < 0.35

0.35 ≤ t < 0.40

0.40 ≤ t < 0.45

0.45 ≤ t < 0.50

Unit 16Data Presentation

Histograms with Unequal Class

You can not draw histograms with equal intervals as the data is not given in this way. So for each of the intervals, you need to give:

Weight (grams) Frequency

0 ≤ w < 40 5

40 ≤ w < 50 6

50 ≤ w < 60 8

60 ≤ w < 70 4

70 ≤ w < 100 2

Weight (grams) Frequency Frequency Density

0 ≤ w < 40 5

40 ≤ w < 50 6

50 ≤ w < 60 8

60 ≤ w < 70 4

70 ≤ w < 100 2

Now you can draw the histogram

Weight (grams) Frequency Frequency Density

0 ≤ w < 40 5

40 ≤ w < 50 6

50 ≤ w < 60 8

60 ≤ w < 70 4

70 ≤ w < 100 2