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3. Histograms Histograms are different to bar charts. Bar charts are frequency diagrams that show categories along the horizontal axis, whereas histograms are frequency diagrams that show grouped data values along the horizontal axis. Histograms can be used to show both discrete and continuous data. Walk Bike Bus Car Frequenc y MTWT F S S Pupils travelling to school Meals sold during the week. Frequenc y 12 3 4 5 66+ Number of pets owned. Bar Charts Runs 0-9 10-19 Temperature ( o C) 10 14 18 22 26 28 32 Frequency Histograms Grouped Data Runs scored in matches by a batsman last season. Maximum daytime Temperature 20-2930-39 40-49 50-59 Discrete data. Continuous data

4. Use the histogram to determine how many cricket matches the batsman played last season. Histograms for Discrete Data Frequency Runs Scored 0 - 19 5 10 15 20 Runs scored by an opening batsman in one-day cricket matches last season. 20 - 39 40 - 59 60 - 7980 - 100 5 9 16 40 8 2

5. Use the histogram to determine how many times the batsman scored 40 runs or more. Histograms for Discrete Data Frequency Runs Scored 0 - 19 5 10 15 20 Runs scored by an opening batsman in one-day cricket matches last season. 20 - 39 40 - 59 60 - 7980 - 100 16 8 2 26

6. The histogram shows that the batsman scored 50 runs in some of the matches. True or false? Discuss Histograms for Discrete Data Frequency Runs Scored 0 - 19 5 10 15 20 Runs scored by an opening batsman in one-day cricket matches last season. 20 - 39 40 - 59 60 - 7980 - 100 False

7. The histogram below shows the number of marks scored in a maths test by some students. Frequency 5 10 15 20 25 Histograms for Discrete Data(2) 0 10 20 30 40 50 Marks Test Scores 60

8. Use the histogram to determine the total number of students that wrote the test. Frequency 5 10 15 20 25 Histograms for Discrete Data(2) 0 - 9 10 - 19 20 - 29 30 - 39 40 - 49 50 - 60 Marks Test Scores 4 15 65 23 14 8 1

9. Use the histogram to determine how many students passed the test if the pass mark was 30. Frequency 5 10 15 20 25 Histograms for Discrete Data(2) 0 - 9 10 - 19 20 - 29 30 - 39 40 - 49 50 - 60 Marks Test Scores 14 8 1 23

10. Drawing a Histogram from raw data. FrequencyTallyRuns Too many! Too few! Groups of between 6 and 9 look best. 100 - 119 80 - 99 60 - 79 40 - 59 20 - 39 0 - 19 1. Choose a suitable grouping and display in a frequency table. The following data shows the number of runs scored by an opening batsman during matches last season. 42 34 39 49 62 99 18 24 37 38 59 112 47 72 85 68 53 101 45 12 0 33 42 61 80 30 21 27 56 90 5 35 94 63 75 33 20 44 33 71

11. Drawing a Histogram from raw data. The following data show the number of runs scored by an opening batsman during matches last season. 42 34 39 49 62 99 18 24 37 38 59 112 47 72 85 68 53 101 45 12 0 33 42 61 80 30 21 27 56 90 5 35 94 63 75 33 20 44 33 71 FrequencyTallyRuns 100 - 119 80 - 99 60 - 79 40 - 59 20 - 39 0 - 19 1. Choose a suitable grouping and display in a frequency table. 2. Complete the frequency table then draw the histogram. 0-1920-39 40-59 60-79 80-99 100-119 Runs Scored 2 5 7 9 13 4 f 5 10 15 0 Runs scored in matches

12. 1020 30 40 50 60 70 Height (cm) The following data shows the height (as measured to the nearest cm) of a random selection of cut flowers from Becky’s Flower Shop. 42 34 39 49 62 69 28 24 37 38 59 55 47 15 42 68 53 30 45 29 1 0 33 42 61 31 30 21 27 56 50 1 5 35 54 33 45 33 20 44 33 31 FrequencyTally Height (h) in cm Drawing a Histogram from raw data. 1. Choose a suitable height intervals & display in a frequency table. 2. Complete the frequency table then draw the histogram. f 5 10 15 0 4 6 8 13 6 3 60  h  < 70 50  h  < 60 40  h  < 50 30  h  < 40 20  h  < 30 10  h  < 20 Heights of Flowers