2. Organizing Data Once it is collected, data can be organized in a table. The number of days each student in a class of 25 was recorded as follows: 0, 3, 1, 0, 4, 2, 1, 3, 5, 0, 2, 0, 0, 0, 4, 0, 1, 1, 2, 1, 0, 7, 3, 1, 0 This data would be easier to analyze if it was in a table. 1 0 1 2 3 3 6 9 Total Frequency25 Sometimes data is grouped into specific intervals. Test scores for a class of 32 were recorded as follows: 90, 85, 74, 86, 65, 62, 100, 95, 77, 82, 50, 83, 77, 93, 73, 72, 98, 66, 45, 100, 50, 89, 78, 70, 75, 95, 80, 78, 83, 81, 72, 75 6 8 11 4 0 3 Total Frequency32

3. Stem and Leaf Plots Let’s put the test score example into a Stem and Leaf Plot. Student test scores: StemLeaf 90, 85, 74, 86, 65, 62, 100, 95, 77, 82, 50, 83, 77, 93, 73, 72, 98, 66, 45, 100, 50, 89, 78, 70, 75, 95, 80, 78, 83, 81, 72, 75 10 9 8 7 6 5 4 0, 0 Enter the data into the table. 0, 5, 3, 8, 5 5,6,2,3,9,0,3,1 4, 7, 7, 3, 2, 8, 0, 5, 8, 2, 5 5, 2, 6 0, 0 5 Arrange the leafs in numerical order. StemLeaf 10 9 8 7 6 5 4 0, 0 0, 3, 5, 5, 8 0, 1, 2, 3, 3, 5, 6, 9 0, 2, 2, 3, 4, 5, 5, 7, 7, 8, 8 2, 5, 6 0, 0 5 Make a key. Key

4. More Stem and Leaf Plots Organize the following data, which represents the number of hours in a month spent watching television for 15 people, into a Stem and Leaf Plot. 135, 107, 144, 90, 158, 133, 101, 147, 151, 142, 109, 145, 113, 155, 110 StemLeaf 9 10 11 12 13 14 15 1, 7, 9 0, 3 3, 5 2, 4, 5, 7 1, 5, 8 0 Key What is the greatest number of hours spent watching television in a month? 158 hours What is the least number of hours spent watching television in a month? 90 hours How many people spend at least 130 hours watching television in a month? 9 people What percentage of people spend 100 hours and 120 hours watching television in a month? What is the range of hours spent watching television in a month? From 90 to 158 hours

5. Histograms A Histogram is a vertical bar graph in which each interval is represented by the width of the bar and the frequency is represented by the height of the bar. Let’s look at the test score example again. Test Scores of 32 Students Test Scores ( Intervals) Frequency 41-50 51-60 61-70 71-80 81-90 91-100 12 11 10 9 8 7 6 5 4 3 2 1 0

6. Another Histogram The following table represents the number of miles per gallon obtained by 40 drivers. Miles per Gallon for 40 Drivers Mileage (Miles per Gallon) Frequency 16-19 20-23 24-27 28-31 32-35 36-39 40-43 12 11 10 9 8 7 6 5 4 3 2 1 0

7. Cumulative Histogram The following table represents test scores of 240 students in a school. Test Scores Frequency 51-60 61-70 71-80 81-90 91-100 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Now let’s make a Cumulative Frequency Table. Cumulative Histogram Test Scores 51-60 61-70 71-80 81-90 91-100 Frequency 240 220 200 180 160 140 120 100 80 60 40 20 0

8. More Cumulative Histograms The following table represents the number of book students bring home. Cumulative Number of Books Brought Home Number of Books 0 1 2 3 4 5 6 7 Frequency 25 20 15 10 5 0

9. More Cumulative Histograms The following table represents the number of book students bring home. Cumulative Number of Books Brought Home Number of Books 0 1 2 3 4 5 6 7 Frequency 30 25 20 15 10 5 0