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