Mean, Median, Mode, and Range LESSON 1-10 Problem of the Day 1. Vocabulary Review When you simplify 2 + 6 ÷ 3, which operation should you use first? Find the value of each expression. 2. (7 + 19) ÷ 2 3. 4. –9 + 4 • 2 –1 –14 + 6 2 1-10

Mean, Median, Mode, and Range LESSON 1-10 Check Skills You’ll Need Solutions 1. division 2. (7 + 19) ÷ 2 = 26 ÷ 2 = 13 3. 4. –9 + 4 • 2 –1 = –9 + 8 –1 = –2 –14 + 6 2 –8 2 = –4 = 1-10

Lesson 1-10 Mean, Median, Mode, and Range These are all ways that we can draw conclusions from data. Mean: average of all data items  get the sum of the data, then divide by the number of items

Mean, Median, Mode, and Range LESSON 1-10 Additional Examples Find the mean of 502, 477, 593, 481, 735, and 614. 502 + 477 + 593 + 481 + 735 + 614 6 Divide the sum by the number of terms. Simplify. 3,402 6 = 567 Quick Check 1-10

Lesson 1-10 Mean, Median, Mode, and Range Outlier: a data item that is very different from the other data items (much higher or lower) Outliers can result in a misleading mean Example: 15, 12, 14, 17, 13, 24, 12, 15 What is the outlier?

Lesson 1-10 Mean, Median, Mode, and Range Median: the middle value in the data set You MUST arrange the data in numerical order first With an even number of data items, get the mean of the two middle values

Mean, Median, Mode, and Range LESSON 1-10 Additional Examples Find the median of the data in the chart. 18 Responses to “How many pets do you have?” 2 0 1 2 4 2 1 0 3 2 0 8 0 1 2 3 0 1 First write the data in order from least to greatest. 0 0 0 0 0 1 1 1 1 2 2 2 2 2 3 3 4 8 The two middle values are 1 and 2. Find the mean of the two middle values. 1 + 2 2 = 1.5 The median is 1.5. Quick Check 1-10

Lesson 1-10 Mean, Median, Mode, and Range Mode: the item that occurs most frequently You can have more than one mode. (When?) Can you have no mode for a data set? (When?)

Mean, Median, Mode, and Range LESSON 1-10 Additional Examples Find the mode of the data in the chart. 18 Responses to “How many pets do you have?” 2 0 1 2 4 2 1 0 3 2 0 8 0 1 2 3 0 1 Make a table to organize the data. 0 pet 1 pet 2 pets 3 pets 4 pets 8 pets There are two modes, 0 and 2. Quick Check 1-10

Lesson 1-10 Mean, Median, Mode, and Range Range: the difference between the greatest and least data items Shows how spread out the data is

Mean, Median, Mode, and Range LESSON 1-10 Additional Examples Temperatures one day in January ranged from – 7°F to 11°F. What was the temperature range? 11 – (–7) = 11 + 7 Add the opposite of –7, which is 7. = 18 Simplify. The temperature range was 18°F. Quick Check 1-10

Mean, Median, Mode, and Range LESSON 1-10 Lesson Quiz Find the mean, median, mode, and range of each set of data. 1. 25  27  21  27   20 2. –8  –4  2  10  –10 3. 7.5  3.6  15.4  3.6  15.4 mean, 24; median, 25; mode, 27; range, 7 mean, –2; median, –4; mode, no mode; range, 20 mean, 9.1; median, 7.5; mode, 3.6 and 15.4; range, 11.8 1-10

Lesson 1-10 Mean, Median, Mode, and Range Homework: Activity Lab 1-10 Lesson 1-10, p. 55 #s 1-8 all; 10-22 evens; 25, 33