Histograms StemLeaf Plots Kinda like bar graphs but
Histograms & Stem-Leaf Plots Kinda like bar graphs but just a lil’ different.
Stem and Leaf plot Keelan, a pro athlete, scores every time he steps on the court. His points per game throughout the season are listed below: 4, 5, 8, 13, 17, 19, 20, 21, 24, 28, 31, 32, 35 The “stem” is the tens place, the “leaf” is the ones place. Stem 0 1 2 3 Leaf 4, 5, 8 3, 7, 7, 9 0, 0, 1, 4, 8 1, 2, 5
Stem and Leaf plot List of student grades. Make a stem and leaf plot. Stem Leaf 5 8 6 6, 8 7 2, 7, 7 8 5, 8, 9 9 1, 1, 5 • What was the student’s lowest grade? • What was the student’s highest grade? • How many failing grades does the student have?
Team A: 65, 42, 56, 49, 58, 42, 61, 55, 45, 72 Team B: 57, 60, 48, 49, 52, 61, 58, 37, 63, 48 Team. Football A Team State B Championship 3 7 Scores 9522 4 889 865 5 278 51 6 013 2 7 Key: |4|8 means 48 2|4| means 42 The tens digits are the stems. The ones digits are the leaves. Put Team A’s scores on the left side and Team B’s scores on the right. Title the graph and add a key.
Theme Park Attendance by Age People 78 97 155 198 189 123 80 58 31 15 12 8 5 2 Ages of People at Busch Gardens 250 200 Number of People Age 0 -5 6 -10 11 -15 16 -20 21 -25 26 -30 31 -35 36 -40 41 -45 51 -55 56 -60 61 -65 66 -70 70+ 150 100 50 0 0 -5 6 -10 11 -15 16 -20 21 -25 26 -30 31 -35 36 -40 41 -45 51 -55 56 -60 61 -65 66 -70 Age 70+
Theme Park Attendance by Age This data is Skewed. It has a tendency towards one side. In this case, it is positive skewed (leaning left) Negative skew leans right.
Characteristics of Frequency Tables and Histograms Frequency Tables: Range of values split evenly. (Ex: goes up by 5 each time 1 -5, 6 -10…) • Histograms: • Like a bar graph. • The bars are touching.
Frequency of landing heads after 20 coin flips Frequency Heads Frequency 0 -2 0 3 -5 1 6 -8 5 9 -11 8 12 -14 4 3 15 -17 2 2 18 -20 0 9 8 7 6 5 4 1 0 0 -2 3 -5 6 -8 9 -11 12 -14 15 -17 18 -20
Frequency of landing heads after 20 coin flips This data is distributed normally. A Normal distribution is centered
Number of Customers in a Restaurant During the Day Number of Customers at a Restaurant 60 Number of Customers 50 40 30 20 10 0 : 0 11 0 - 10 : 0 -1 0: 00 0 00 9: 09 : 0 0 8: 0 08 : 0 0 7: 0 07 : 0 06 : 0 05 5: 0 Time 6: 0 0 0 4: 0 04 : 0 0 3: 0 03 2: 0 02 : 0 00 1: 0: 0 1: 0 0 : 0 12 12 0: 0 0 0 11 Time 11: 00 -12: 00 -1: 00 -2: 00 -3: 00 -4: 00 -5: 00 -6: 00 -7: 00 -8: 00 -9: 00 -10: 00 -11: 00 # of Customers 15 35 51 36 13 15 24 37 57 31 18 6
Number of Customers in a Restaurant During the Day This is a bimodal distribution. It has two peaks.
ON YOUR OWN PAPER
How to make Frequency Tables The numbers of students enrolled in Western Civilization classes at a university are given below. Use the data to make a frequency table with intervals. 12, 22, 18, 9, 25, 31, 28, 19, 22, 27, 32, 14 Step 1: Identify the least and greatest values. The least value is 9. The greatest value is 32.
How to make Frequency Tables Step 2: Divide the data into equal intervals. For this data set, use an interval of 10. Step 3 List the intervals in the first column of the table. Count the number of data values in each interval and list the count in the last column. Give the table a title. Enrollment in Western Civilization Classes Number Frequency Enrolled 1 – 10 11 – 20 21 – 30 31 – 40 1 4 5 2
How to make a Histogram A histogram is a bar graph used to display the frequency of data divided into equal intervals. The bars must be of equal width and should touch, but not overlap.
How to make a Histogram Use the frequency table in Example 2 to make a histogram. Step 1: Use the scale and interval from the frequency table. Step 2: Draw a bar for the number of classes in each interval. All bars should be the same width. The bars should touch, but not overlap. Enrollment in Western Civilization Classes Number Frequency Enrolled 1 – 10 11 – 20 21 – 30 31 – 40 1 4 5 2
Pick a number between 1 -50 Stem Leaf 0 1 Create a frequency Table Number 2 0 -9 3 10 -19 4 5 20 -29 30 -39 40 -50 Frequency
Making a Histogram from a frequency Table 10 Histogram Practice 8 Frequency 6 4 2 0 0 -9 -2 10 -19 20 -29 Number 30 -39 40 -50
Year Age 2017 0 2012 5 Make a list of the ages of your pennies. 2007 10 2002 15 Create a stem and leaf plot of the ages. 1997 20 1992 25 Create a frequency table of the ages. 1987 30 1982 35 Create a histogram of the ages. 1977 40 1972 45 1967 50 Pennies
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