2. Transparency 7 Click the mouse button or press the Space Bar to display the answers.

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4. Example 7-4b Objective Find the median, mode, and range of a set of data

5. Example 7-4b Vocabulary Median The middle number of an ordered set (odd set of data) Or The mean of the middle two numbers of an ordered set (even set of data)

6. Example 7-4b Vocabulary Mode The number(s) that occur most often

7. Example 7-4b Vocabulary Range The difference between the greatest and the least value of the set

8. Lesson 7 Contents Example 1Find Median and Mode Example 2Find Mean, Median, and Mode Example 3Use Mean, Median, and Mode Example 4Find Range

9. Example 7-1a NUTRITION The table shows the Calorie content of various vegetables. Find the median and mode of the data. Calories of Selected Vegetables (per serving) 153550 31525 852520 551540 1/4 Order data from least to greatest 5, 15, 15, 20, 25, 25, 31, 35, 40, 50, 55, 85

10. Example 7-1b 1/4 5, 15, 15, 20, 25, 25, 31, 35, 40, 50, 55, 85 Count the pieces of data and divide by 2 12 divided by 2 = 6 Beginning at smallest number, underline 6 pieces of data Beginning at largest number, underline 6 pieces of data Circle the 2 middle numbers Find the mean of the numbers Add numbers and divide by 2 median: 28

11. Example 7-1b 5, 15, 15, 20, 25, 25, 31, 35, 40, 50, 55, 85 1/4 NUTRITION The table shows the Calorie content of various vegetables. Find the median and mode of the data. Use the numbers ordered from least to greatest There are 2 modes: 15 and 25 Answer: median = 28 mode = 15 and 25

12. Example 7-1c COLLEGE The table shows the ages of students in a science class at a local community college. Find the median and mode of the data. Student Age 20 21 19 35 19 20 19 18 24 19 18 23 Answer: Median = 19.5 Mode = 19 1/4

13. Example 7-2a MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the age survey data 24, 30, 38, 33, 19, and 24, respectively? A 24, 24, 24 B 26, 54, 24 C 27, 28, 24 D 28, 27, 24 Read the Test Item You need to find the mean, median, and mode of the data. 2/4

14. Example 7-2b Mean 2/4 MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the age survey data 24, 30, 38, 33, 19, and 24, respectively? Mean = sum of data pieces of data Mean = 24 + 30 + 38 + 33 + 19 + 24 Put data in numerator Count number of data and put in denominator 6 Add numerator Mean = 168 Bring down 6 6

15. Example 7-2b Mean 2/4 MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the age survey data 24, 30, 38, 33, 19, and 24, respectively? Divide numerator by denominator Mean = 168 6 Mean = 28

16. Example 7-2b Median 2/4 MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the age survey data 24, 30, 38, 33, 19, and 24, respectively? Order numbers from least to greatest 19, 24, 24, 30, 33, 38 Count the pieces of data and divide by 2 6 divided by 2 = 3 Beginning at smallest number, underline 3 pieces of data Beginning at largest number, underline 3 pieces of data Circle the 2 middle numbers

17. Example 7-2b Median 2/4 MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the age survey data 24, 30, 38, 33, 19, and 24, respectively? 19, 24, 24, 30, 33, 38 Find the mean of the numbers Median = 24 + 30 2 Add numerators Median = 54 2 Bring down the 2 Divide numerator by denominator Median = 27

18. Example 7-2b Mode 2/4 MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the age survey data 24, 30, 38, 33, 19, and 24, respectively? 19, 24, 24, 30, 33, 38 Use the numbers listed from least to greatest Look for numbers that occur most often 24 is the only number that occurs more than once Mode = 24

19. Example 7-2b The mean = 28, the median = 27, and the mode = 24. Answer: D A 24, 24, 24 B 26, 54, 24 C 27, 28, 24 D 28, 27, 24 2/4 MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the age survey data 24, 30, 38, 33, 19, and 24, respectively? Choose the letter that best represents the answer

20. Example 7-2c A 15, 18, 18 B 17, 18, 18 C 17, 16, 18 D 16, 17, 18 MULTIPLE-CHOICE TEST ITEM What are the mean, median, and mode of the quiz score data 18, 14, 16, 18, and 19, respectively? Answer: B 2/4

21. Example 7-3a CLIMATE The average annual number of days of precipitation for selected cities in the Southwest is shown in the table below. Which measure of central tendency best describes the data? Average Annual Precipitation (days) in Selected Southwestern U.S. Cities 59327226 36 52 904363 Must find the mean, median, and mode to answer question 3/4

22. Example 7-3a Average Annual Precipitation (days) in Selected Southwestern U.S. Cities 59327226 36 52 904363 Add the columns 3/4 Mean = sum of data pieces of data Mean = 185 +111 +187 +78 Count the number of pieces of data and put in the denominator 11 Add the numerator Mean = 561 Bring down denominator11 Divide Mean = 51

23. Example 7-3a Average Annual Precipitation (days) in Selected Southwestern U.S. Cities 59327226 36 52 904363 3/4 Median Order numbers from least to greatest 26, 32, 36, 36, 43, 52, 52, 59, 63, 72, 90 Count the pieces of data and divide by 2 11 divided by 2 = 5.5 Beginning at smallest number, underline 5 pieces of data Beginning at largest number, underline 5 pieces of data Circle the middle number Median = 52

24. Example 7-3a Average Annual Precipitation (days) in Selected Southwestern U.S. Cities 59327226 36 52 904363 3/4 Mode Use the numbers from median that are ordered from least to greatest 26, 32, 36, 36, 43, 52, 52, 59, 63, 72, 90 Mode = 36 and 52 Look for numbers that occur most often 36 and 52 occur twice and no others occur more often

25. Example 7-3b Answer: Mean and median describes the data best 3/4 CLIMATE The average annual number of days of precipitation for selected cities in the Southwest is shown in the table below. Which measure of central tendency best describes the data? Mean = 51 Median = 52 Mode = 36 and 52 Since 51 and 52 appear in the middle of the set of data either could describe the data If the mode was only 52 it could be used, but 36 also as the mode separates the mode from the rest of the data

26. Example 7-3c WEIGHT The weights (in pounds) of nine sixth-grade boys are shown below. Which measure of central tendency best describes the data? Answer: The median of 79 best describes the data. Weight (in pounds) of Sixth-Grade Boys 786883 757990 1227681 3/4

27. Example 7-4a Find the range of the data set 65, 68, 72, 65, 80, 55, 65. Then write a sentence describing how the data vary. Range = Greatest number - least number Range = 25. The range tells us that the data are fairly closely grouped together. Range = 80 Range = 25 4/4 Greatest number ? Range = 80 - 55 Least number ? Subtract Answer:

28. Example 7-4b Find the range of the data set 25, 74, 48, 32, 61, 54. Then write a sentence describing how the data vary. Answer: Range = 49 The range shows the data are fairly spread out. * 4/4

29. End of Lesson 7 Assignment Lesson 2:7 Median, Mode, and Range 9 - 18 All