Mean, Median, and Range From Data Displays - Step-by-Step Lesson

Transcription

1 Mean, Median, and Range From Data Displays - Step-by-Step Lesson The dot plot shows the number of oranges each person ate. Describe the data by explaining the mean, median and range. Explanation: Step 1) The "mean" is the average of the data. To find the mean, add up all the data and then divide by the number of instances of the data you have. Mean = The middle value of the data is called the median. The first step to determining the median is to order the data from least to greatest. 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 5, 5, 5, 5, 5, 6 Median = The difference between the smallest and largest data is called the range. Step 2) mean = = = pieces of data Median = = = 9 (This means the median is the 9th number in the data list) 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 5, 5, 5, 5, 5, 6 Range = 6-1 = 5

2 Mean, Median, and Range from Data Displays - Guided Lesson Complete the following problems: 1) Madeline checked the available RAM on 6 computers in the computer lab. The amounts were: 3 GB 6 GB 5 GB 4 GB 2 GB 1 GB 1 GB What was the median amount of memory available? 2) The gym teacher made a table showing the ages of her student. What is the median age of her students? Age Jack Mike Alien Gordon Paul 3) The table shows the number of days math students attended extra help after school. What is the mean, median and range for the data set? Student Days Attended Smith 15 Johnson 17 Jones 20 Davis 16

3 Mean, Median, and Range from Data Displays - Guided Lesson Explanation Explanation #1 Let s first find the position within the data of where the median lies. Median position = Step 3) = = 4 (This means the data at the 4 th position numerically in order is the median.) 1 GB 1 GB 2 GB 3 GB 4 GB 5GB 6 GB Answer is: 3 GB Explanation #2 Once again, let s focus on finding the position of the median first and then we can arrange the data and determine its value. Median = Step 3) = = 3 (median is at the 3rd position in the data set) Jack (3) Mike (4) Gordon (5) Paul (6) Alien (7) The answer is: Gordon

4 Explanation #3 The mean is just the average. We can find this by simply applying this formula: Mean = mean = = 17 The median is the middle value of the data set. We can find the position the median lies within the data set by using: Median = Median = = = 2.5 (This indicates that the median lies between the average of the second and third position in the data set) 15, 16, 17, 20 (If we take the average of those two positions, we will find the median) = = 16.5 The range is the easiest one. Just subtract the smallest value from the largest value in the data set. Range = 20 (high) - 15 (low) = 5

5 Mean, Median, and Range From Data Displays - Independent Practice Worksheet Complete all the problems. 1. The table shows the number of toys each child has. What is the mean, median and range? Child Number of Toy Miller 8 Wilson 9 Taylor 7 Thomas The tourist guide made a graph showing the height of its members. What is the median of the numbers? 8 Height Height 0 Hall Lee Walker Lopez Perez 3. A shop keeper checked the size of the water bottles in his shop. The amounts were: 6 Lt 8 Lt 12 Lt 9 Lt 7 Lt 10 GB 14 GB What is the mean?

6 4. This is a list of the number of shirts each child has. What is the mean? 12, 14, 13, 14, 15, 16, 11, The soccer coach made a graph showing the weight of his players. What is the median of the data? Weight Scott Allen Adams Robert Parker Weight Cooper has a candy shop. He counts the number of candies in the bags. The amounts were: What is the range? 7. The table shows the number of pencils per student. What is the mean, median? Student Number of Pencils Bailey 4 Morgan 2 Ward 5 Sanchez 7 Collins 10

7 8. The dot plot shows the number of shoes each person has. Describe the data What is the mean, median and range? 9. The boss made a graph showing the number of days each worker was absent last month. What is the median of the data? 7 Absent Absent Gray James Price Kelly Ross Barnes 10. Mr. Davis collected donations for charity. The amounts given by each donor is listed below. What is the range? $50, $52, $64, $32, $22, $80, $48, $30, $60

8 Mean, Median, and Range From Data Displays - Matching Worksheet Match the problems to their answers. 1. The square plot shows the number of texts Simmons sent each day. What is the mean? a The table shows the number points scored in a series of cricket matches. What is the median? Match Number of Scores I 80 II 70 III 65 IV 100 b. 3.5 V The table shows the number of mangoes your tree produced each year. What is the range of the data? c. 80 Year Number of Mango