LESSON 8.1 Two-Way Frequency Tables Name 8.1 HARDBOUND SE PAGE 279 BEGINS HERE Summarize categorical data for two categories in two-way frequency tables. Interpret relative frequencies in the context of the data (including joint, marginal, and conditional relative frequencies). Recognize possible associations and trends in the data. Categorical Data and Frequencies Circle the categorical data variable. Justify your choice. temperature weight height color Temperature, weight, and height are measured on a numerical scale, so they are Mathematical Practices quantitative data. Color cannot be expressed numerically. MP.7 Using Structure Language Objective Identify whether the given data is categorical or quantitative. large, medium, small categorical Distinguish between quantitative data and categorical data. 2 2 120 ft , 130 ft 2, 140 ft quantitative ENGAGE View the Engage section online, and then take a quick, show-of-hands survey to determine the most popular sports among the students in your class. Discuss whether the survey results might have been different had you surveyed the boys and the girls separately. Then preview the Lesson Performance Task. A frequency table shows how often each item occurs in a set of categorical data. Use the categorical data listed on the left to complete the frequency table. © Houghton Mifflin Harcourt Publishing Company Ways Students Get to School bus car walk car car car bus walk walk walk bus bus car bus bus walk bus car bus car Way Frequency bus 8 car 7 walk 5 Reflect 1. How did you determine the numbers for each category in the frequency column? You can determine the numbers for each category by counting the number of times each category is listed in the data. 2. What must be true about the sum of the frequencies in a frequency table? The sum should equal the total number of items in the data set. Module 8 be ges must EDIT--Chan DO NOT Key=NL-A;CA-A Correction Lesson 1 347 gh “File info” made throu Date Class 8.1 ion: How Quest Essential rical data can catego arized? ries be summ for two catego rds, of these standa see the table starting on Resource Locker page CA2. uencies HARDCOVER PAGES 279290 ne you will exami In this lesson animal type, ing itative data. ts are quant numbers. Data describ Explore measuremen using numerical expressed sed with cannot be can be expres rical data, which categorical data. Data that of examples data, or catego qualitative or favorite song are . car, model of your choice S-ID.5 For IN1_MNLESE389755_U4M08L1.indd 347 cy Tables Frequen Two-Way Name the full text Data Categorical data categorical temperature and Freq Turn to these pages to find this lesson in the hardcover student edition. Justify variable. color height they are scale, so a numerical ured on t are meas y. t, and heigh numericall re, weigh expressed Temperatu cannot be Color data. e . quantitativ or quantitative is categorical data er the given l Identify wheth categorica m, small large, mediu titative 2 quan the data. Use 2 ft2 , 140 ft categorical 120 ft , 130 in a set of item occurs ncy table. often each the freque shows how to complete ncy table A freque on the left data listed Frequency categorical Way 8 l bus Get to Schoo nts Ways Stude 7 Circle the weight car walk 5 Harcour t Publishin y g Compan bus car car car bus car walk bus bus car walk car walk walk bus car bus bus bus walk n? each ncy colum of times in the freque number category ting the ers for each ory by coun ine the numb each categ did you determ the numbers for 1. How determine You can table? in the data. frequency is listed ncies in a set. category freque data in the sum of the of items about the number must be true l the total 2. What should equa Lesson 1 The sum © Houghto n Mifflin Reflect 347 Module 8 8L1 347 55_U4M0 ESE3897 IN1_MNL 347 Lesson 8.1 Resource Locker Data that can be expressed with numerical measurements are quantitative data. In this lesson you will examine qualitative data, or categorical data, which cannot be expressed using numbers. Data describing animal type, model of car, or favorite song are examples of categorical data. S-ID.5 PREVIEW: LESSON PERFORMANCE TASK Two-Way Frequency Tables Explore The student is expected to: You can summarize categorical data for two categories in a two-way frequency table. Date Essential Question: How can categorical data for two categories be summarized? Common Core Math Standards Essential Question: How can categorical data for two categories be summarized? Class 4/9/14 5:58 PM 4/2/14 9:30 AM Explain 1 HARDBOUND SE Constructing Two-Way Frequency Tables PAGE 280 BEGINS HERE If a data set has two categorical variables, you can list the frequencies of the paired values in a two-way frequency table. Example 1 Categorical Data and Frequencies Complete the two-way frequency table. A high school’s administration asked 100 randomly selected students in the 9th and 10th grades about what fruit they like best. Complete the table. INTEGRATE TECHNOLOGY Preferred Fruit Grade Apple Orange Banana 9th 19 12 23 10th 22 9 15 Students have the option of completing the Explore Activity online or in the book. Total Total CONNECT VOCABULARY Row totals: Column totals: Grand total: 9th: 19 + 12 + 23 = 54 Apple: 19 + 22 = 41 Sum of row totals: 54 + 46 = 100 10th: 22 + 9 + 15 = 46 Orange: 12 + 9 = 21 Sum of column totals: 41 + 21 + 38 = 100 Banana: 23 + 15 = 38 Both sums should equal the grand total. Make sure that students understand the distinction between quantitative and categorical data. Quantitative data can be measured on a numbered scale. Categorical data involves either/or choices between two or more descriptive categories. Ask students to provide some examples of quantitative and categorical data. Preferred Fruit Grade Apple Orange Banana Total 9th 19 12 23 54 10th 22 9 15 46 Total 41 21 38 100 Jenna asked some randomly selected students whether they preferred dogs, cats, or other pets. She also recorded the gender of each student. The results are shown in the two-way frequency table below. Each entry is the frequency of students who prefer a certain pet and are a certain gender. For instance, 8 girls prefer dogs as pets. Complete the table. EXPLAIN 1 Gender Dog Cat Other Total Girl 8 7 1 16 Boy 10 5 9 24 Total 18 12 10 40 HARDBOUND SE Row totals: Column totals: Grand total: Girl: 8 + 7 + 1 = 16 Dog: 8 + 10 = 18 Sum of row totals: 16 + 24 = 40 Boy: 10 + 5 + 9 = 24 Cat: 7 + 5 = 12 Sum of column totals: 18 + 12 + 10 = 40 Other: 1 + 9 = 10 Both sums should equal the grand total. 348 Constructing Two-Way Frequency Tables © Houghton Mifflin Harcourt Publishing Company Preferred Pet Module 8 EXPLORE PAGE 281 BEGINS HERE Lesson 1 PROFESSIONAL DEVELOPMENT IN1_MNLESE389755_U4M08L1.indd 348 Integrate Mathematical Practices This lesson provides an opportunity to use Mathematical Practice MP.7, which asks students to “look for and make use of structure.” In this lesson, students use the structure of two-way frequency tables to analyze data and understand a problem-solving situation. 4/2/14 9:40 AM INTEGRATE MATHEMATICAL PRACTICES Focus on Communication MP.3 To check students’ understanding of the information presented in a two-way frequency table, have one student ask a question about the data in the table. Have another student answer the question and provide an explanation of how to use the table to arrive at the answer. QUESTIONING STRATEGIES What is the difference between a two-way frequency table and an ordinary frequency table? In a two-way frequency table, each value (other than row and column totals) indicates the number of items that fit two data categories rather than one, such as the number of boys who prefer cats. In an ordinary frequency table, data values correspond to only one data category. Two-Way Frequency Tables 348 Reflect EXPLAIN 2 3. Look at the totals for each row. Was Jenna’s survey evenly distributed among boys and girls? Explain. No, there were 24 boys and 16 girls. Reading Two-Way Frequency Tables 4. Look at the totals for each column. Which pet is preferred by the most students? Justify your answer. Dogs: the total for Dog is greater than the total for Cat and the total for Other. INTEGRATE MATHEMATICAL PRACTICES Focus on Reasoning MP.2 Remind students that there may be more than Your Turn Complete the two-way frequency table. 5. Antonio surveyed 60 of his classmates about their participation in school activities and whether they have a part-time job. The results are shown in the two-way frequency table below. Complete the table. Activities one process for filling in a particular table. Discuss different ways to fill cells in a table, such as using addition to find the total for a column or row, and working backward to find a missing value that is not a total. 6. Job Clubs Only Sports Only Both Neither Total Yes 12 13 16 4 45 No 3 5 5 2 15 Total 15 18 21 6 60 Jen surveyed 100 students about whether they like baseball or basketball. Complete the table. Like Basketball AVOID COMMON ERRORS Remind students to use the row totals and column totals to check that their work is correct. The sum of the row totals should be the same as the sum of the column totals. If the sums are different, students need to review their work to look for errors. Like Baseball Yes No Total Yes 61 13 74 No 16 10 26 Total 77 23 100 © Houghton Mifflin Harcourt Publishing Company Explain 2 HARDBOUND SE PAGE 282 BEGINS HERE Reading Two-Way Frequency Tables You can extract information about paired categorical variables by reading a two-way frequency table. Example 2 Read and complete the two-way frequency table. Suppose you are given the circled information in the table and instructed to complete the table. Eat Cereal for Breakfast Gender Yes No Total 54 Girl 42 12 Boy 36 10 46 Total 78 22 100 Find the total number of boys by subtracting: 100 - 54 = 46 Find the number of boys who do eat cereal by subtracting: 46 - 10 = 36 Add to find the total number of students who eat cereal and the total number of students who do not eat cereal. Module 8 349 Lesson 1 COLLABORATIVE LEARNING IN1_MNLESE389755_U4M08L1.indd 349 Peer-to-Peer Activity Have students work in pairs. Challenge one in each pair to describe a data set for which the partner must create a two-way frequency table. Students should provide as little direct information as possible, while still making it possible to complete the table. For example, instead of saying, “Twenty boys prefer baseball,” they might say, “The number of boys who prefer baseball is 15 less than the number of girls who prefer softball.” After students complete the frequency tables, have them compare results with their partners. If the students disagree, have them discuss and determine which is correct. 349 Lesson 8.1 2/26/16 2:14 AM B One hundred students were surveyed about which beverage they chose at lunch. Some of the results are shown in the two-way frequency table below. Complete the table. QUESTIONING STRATEGIES To complete a two-way frequency table that is missing information, is it necessary to know the total of all the values in the table? Explain. No; if there is enough other information given in the table, the total can be determined using other information. Lunch Beverage Gender Juice Milk Water Total Girl 10 13 17 40 Boy 15 24 21 60 Total 25 37 38 100 Find the total number of girls by subtracting: 100 - 60 = 40 So, the total number of girls is 40 . The number of girls who do not choose milk is 17 + 10 = 27 . Find the number of girls who chose milk by subtracting: 40 - 27 = 13 Reflect 7. Which lunch beverage is the least preferred? How do you know? Juice: the total for Juice is less than the total for Milk and the total for Water. Your Turn Read and complete the two-way frequency table. 8. 100 students were asked what fruit they chose at lunch. The two-way frequency table shows some of the results of the survey. Complete the table. Lunch Fruit Apple Pear Banana Total Girl 21 17 11 49 Boy 25 10 16 51 Total 46 27 27 100 © Houghton Mifflin Harcourt Publishing Company 9. Gender 200 high school teachers were asked whether they prefer to use the chalkboard or projector in class. The two-way frequency table shows some of the results of the survey. Complete the table. Preferred Teaching Aid Gender Chalkboard Projector Total Female 43 56 99 Male 44 57 101 Total 87 113 200 Module 8 350 HARDBOUND SE PAGE 283 BEGINS HERE Lesson 1 DIFFERENTIATE INSTRUCTION IN1_MNLESE389755_U4M08L1.indd 350 Cognitive Strategies 01/04/14 8:57 PM When students are completing two-way frequency tables that are missing information, discuss how to determine which cells in the table can be completed first. Students should understand that in order for a value to be determined, it must be the only missing value in either its row or its column. By completing a row or column in which only one value is missing, students move one step closer to completing other rows or columns. Two-Way Frequency Tables 350 Elaborate ELABORATE 10. You are making a two-way frequency table of 5 fruit preferences among a survey sample of girls and boys. What are the dimensions of the table you would make? How many entries would you need to fill the table with frequencies and totals? You would make a 2-by-5 for the frequencies. Adding totals would increase the INTEGRATE MATHEMATICAL PRACTICES Focus on Communication MP.3 Have students discuss why the order of words dimensions to 3-by-6. You need 3 times 6, or 18, entries to fill the table. 11. A 3 categories-by-3 categories two-way frequency table has a row with 2 numbers, and no row or column totals. Can you fill the row? This table would be a 4-by-4 table, including the row of totals. You cannot fill the row is important in identifying a cell in a two-way frequency table. For example, students should understand that “people who watch TV but not movies” refers to a different cell than “people who watch movies but not TV. ” because you need 3 numbers to figure out the last one. 12. Essential Question Check-In How can you summarize categorical data for 2 categories? You can use a two-way frequency table. SUMMARIZE THE LESSON Evaluate: Homework and Practice What information is provided by a two-way frequency table, and how is that information organized? A two-way frequency table provides categorical data for two categorical variables, such as color and size or gender and job. Data for one variable is organized in rows, and data for the other variable is organized in columns. The value in each cell of the table identifies the number of items that fit the intersection of the two categories. 1. 100 m, 200 m, 400 m quantitative 2. A theater company asked its members to bring in canned food for a food drive. Use the categorical data to complete the frequency table. BEGINS HERE © Houghton Mifflin Harcourt Publishing Company Cans Donated to Food Drive HARDBOUND SE PAGE 284 • Online Homework • Hints and Help • Extra Practice Identify whether the given data is categorical or quantitative. gold medal, silver medal, bronze medal categorical peas corn peas soup corn corn soup soup corn peas peas corn soup peas corn peas corn peas corn soup corn peas soup corn corn Cans Frequency soup 6 peas 8 corn 11 Complete the two-way frequency table. 3. James surveyed some of his classmates about what vegetable they like best. Complete the table. Preferred Vegetable Grade Carrots Green Beans Celery Total 9th 30 15 24 69 10th 32 9 20 61 Total 62 24 44 130 Module 8 351 Lesson 1 LANGUAGE SUPPORT IN1_MNLESE389755_U4M08L1 351 Connect Vocabulary The word quantitative in the phrase quantitative data shares a root with the word quantity, meaning an amount. The word categorical in the phrase categorical data shares a root with the word category, meaning a descriptive grouping. Categorical data can also be referred to as qualitative data because these data describe qualities or characteristics. The word frequency in the phrase frequency table shares a root with the word frequent, meaning often. Each value in a frequency table shows how often that value falls into a given category. 351 Lesson 8.1 7/25/14 7:44 AM 4. A high school’s extracurricular committee surveyed a randomly selected group of students about whether they like tennis and soccer. Complete the table. EVALUATE Like Tennis 5. Like Soccer Yes No Total Yes 37 20 57 No 16 15 31 Total 53 35 88 ASSIGNMENT GUIDE After a school field trip, Ben surveyed some students about which animals they liked from the zoo. Complete the table. Preferred Animal at a Zoo 6. Grade Lion Zebra Monkey Total 11th 9 15 14 38 12th 4 17 15 36 Total 13 32 29 74 Jill asked some randomly selected students whether they preferred blue, green, or other colors. She also recorded the gender of each student. The results are shown in the two-way frequency table below. Complete the table. Blue Other Total 15 3 10 28 Boy 3 16 6 25 Total 18 19 16 53 Kevin surveyed some students about whether they preferred soccer, baseball, or another sport. He also recorded their gender. Complete the table. HARDBOUND SE PAGE 285 BEGINS HERE Preferred Sport Gender Soccer Baseball Other Total Girl 33 7 10 50 Boy 15 27 7 49 Total 48 34 17 99 Module 8 Exercise Depth of Knowledge (D.O.K.) Mathematical Practices 1–12 1 Recall of Information MP.7 Using Structure 13–14 2 Skills/Concepts MP.3 Logic 15–22 2 Skills/Concepts MP.4 Modeling 23 1 Recall of Information MP.7 Using Structure 24 2 Skills/Concepts MP.3 Logic 3 Strategic Thinking MP.3 Logic 25–26 Exercises 1–2, 23 Example 1 Constructing Two-Way Frequency Tables Exercises 3–12 Example 2 Reading Two-Way Frequency Tables Exercises 13–22, 24–26 Lesson 1 352 IN1_MNLESE389755_U4M08L1.indd 352 Explore Categorical Data and Frequencies of filled cells in a two-way frequency table that makes it possible to complete the table. Work backward from a completed frequency table by removing values one at a time, making sure it is possible to do so while leaving a row or column with only one missing value. Students may discover that completing a frequency table requires that the table have at least as many filled cells as the number of interior cells. © Houghton Mifflin Harcourt Publishing Company 7. Green Girl Practice INTEGRATE MATHEMATICAL PRACTICES Focus on Patterns MP.8 Have students try to find the smallest number Preferred Color Gender Concepts and Skills 01/04/14 8:57 PM Two-Way Frequency Tables 352 8. MULTIPLE REPRESENTATIONS Have students create a two-question survey whose results can be summarized in a two-way frequency table. Students should understand that the questions they choose for their surveys should not allow for open-ended answers. A school surveyed a group of students about whether they like backgammon and chess. They will use this data to determine whether there is enough interest for the school to compete in these games. Complete the table. Like Backgammon Like Chess Yes No Total Yes 10 61 71 No 5 3 8 15 64 79 Total AVOID COMMON ERRORS 9. Remind students that in a two-way frequency table, the total of the values in each row and the total of the values in each column must add up to the same number. Students can check their work for errors by comparing the sum of the row totals to the sum of the column totals. Hugo surveyed some 9th and 10th graders in regard to whether they preferred math, English, or another subject. The results of the survey are in the following table. Complete the table. Preferred Subject Grade Math English Other 9th 40 35 20 Total 95 10th 41 32 17 90 Total 81 67 37 185 HARDBOUND SE PAGE 286 BEGINS HERE © Houghton Mifflin Harcourt Publishing Company • Image Credits: ©Dragon Images/Shutterstock 10. Luis surveyed some middle school and high school students about the type of music they prefer. Complete the table. Preferred Music School Level Country Pop Other Total Middle School 18 13 23 54 High School 7 32 15 54 Total 25 45 38 108 11. Natalie surveyed some teenagers and adults on whether they prefer standard cars, vans, or convertibles. Her results are in the following table. Complete the table. Preferred Car Type Age Standard Van Convertible Total Adults 10 25 9 44 Teenagers 11 7 24 42 Total 21 32 33 86 Module 8 IN1_MNLESE389755_U4M08L1 353 353 Lesson 8.1 353 Lesson 1 7/25/14 7:44 AM 12. Eli surveyed some teenagers and adults on whether they prefer apples, oranges, or bananas. His results are in the following table. Complete the table. Preferred Fruit Age Apple Orange Banana Total Adults 22 12 10 44 Teenagers 24 9 9 42 Total 46 21 19 86 200 students were asked to name their favorite science class. The results are shown in the two-way frequency table. Use the table for the following questions. Favorite Science Class Gender Biology Chemistry Physics Total Girl 42 39 23 104 Boy 19 45 32 96 Total 61 84 55 200 13. How many boys were surveyed? Explain how you found your answer. 96 boys: 104 of the 200 students were girls, so 200 − 104 = 96 of them were boys. 14. Complete the table. How many more girls than boys chose biology as their favorite science class? Explain how you found your answer. 42 − 19 = 23, so 23 more girls than boys chose biology. The results of a survey of 150 students about whether they own an electronic tablet or a laptop are shown in the two-way frequency table. Gender Electronic tablet Laptop Both Neither Total Girl 15 54 10 9 88 Boy 14 35 8 5 62 Total 29 89 18 14 150 15. Complete the table. Do the surveyed students own more laptops or more electronic tablets? The number of boys is 150 − 88 = 62. HARDBOUND SE PAGE 287 BEGINS HERE © Houghton Mifflin Harcourt Publishing Company Device Girls who own both electronic devices: 88 − 9 − 54 − 15 = 10 Boys who own an electronic tablet: 62 − 5 − 8 − 35 = 14; Students own more laptops. 16. Which group had more people answer the survey, boys or students who own an electronic tablet only? Explain. Boys: 62 boys answered the survey, which is more than the 29 people who own an electronic tablet only. Module 8 IN1_MNLESE389755_U4M08L1 354 354 Lesson 1 7/25/14 7:44 AM Two-Way Frequency Tables 354 17. The table shows the results of a survey about students’ preferred frozen yogurt flavor. Complete the table, and state the flavors that students preferred the most and the least. Preferred Flavor Gender Girl Boy Total Vanilla 12 Mint Strawberry 15 18 Total 45 17 25 55 29 40 13 31 100 Students preferred mint the most and vanilla the least. 18. Teresa surveyed 100 students about whether they like pop music or country music. Out of the 100 students surveyed, 42 like only pop, 34 like only country, 15 like both pop and country, and 9 do not like either pop or country. Complete the two-way frequency table. Like Pop Like Country Yes No Total Yes 15 42 57 No 34 9 Total 49 51 100 43 19. Forty students in a class at an international high school were surveyed about which non-English language they can speak. Complete the table. Foreign Language Gender Girl Boy Total Chinese Spanish 7 8 French 7 Total 22 5 12 6 7 18 14 14 40 HARDBOUND SE PAGE 288 BEGINS HERE © Houghton Mifflin Harcourt Publishing Company Luis surveyed 100 students about whether they like soccer. The number of girls and the number of boys completing the survey are equal. 20. Complete the table. Likes Soccer Gender Girl Boy Total 35 Total 50 50 45 55 100 20 Likes Tennis IN1_MNLESE389755_U4M08L1 355 Lesson 8.1 No 21. Twice as many girls like soccer as the number that like tennis. The same number of students like soccer as like tennis. Construct a table containing the tennis data. Module 8 355 Yes 30 15 Gender Yes No Total Girl 15 35 50 Boy 30 20 50 Total 45 55 100 355 Lesson 1 7/25/14 7:44 AM 22. A group of 200 high school students were asked about their use of email and text messages. The results are shown in the two-way frequency table. Complete the table. Text Messages Email Yes No Total Yes 72 18 90 65 45 110 137 63 200 No Total 23. Circle the letter of each data set that is categorical. Select all that apply. A. 75°, 79°, 77°, 85° B. apples, oranges, pears C. male, female D. blue, green, red E. 2 feet, 5 feet, 12 feet F. classical music, country music G. 1 centimeter, 3 centimeters, 9 centimeters 24. Explain the Error Find the mistake in completing the two-way frequency table for a survey involving 50 students. Then complete the table correctly. Favorite Foreign Language Class Russian German Italian Total Girl 8 8 8 24 Boy 42 9 7 58 Total 50 © Houghton Mifflin Harcourt Publishing Company Gender Possible answer: 50 was used as the total whose favorite is Russian instead of as the grand total. Total boys: 50 - 24 = 26 Boys who prefer Russian: 26 - 9 - 7 = 10 Correct table: Favorite Foreign Language Class Gender Russian German Italian Total Girl 8 8 8 24 Boy 10 9 7 26 Total 18 17 15 50 Module 8 IN1_MNLESE389755_U4M08L1 356 356 Lesson 1 7/25/14 7:44 AM Two-Way Frequency Tables 356 JOURNAL Have students explain the steps they take to complete a two-way frequency table that has missing values. Students should be sure to include descriptions of how to determine column totals and row totals. HARDBOUND SE H.O.T. Focus on Higher Order Thinking PAGE 289 BEGINS HERE 25. Justify Reasoning Charles surveyed 100 boys about their favorite color. Of the 100 boys surveyed, 44 preferred blue, 25 preferred green, and 31 preferred red. a. Explain why it is not possible to make a two-way frequency table from the given data. Charles only surveyed boys, so there is only one categorical variable: color. You need two categorical variables to make a two-way frequency table. b. Suppose Charles also surveyed some girls. Of the girls surveyed, 30 preferred blue and 43 preferred green. Can Charles make a two-way frequency table now? Can he complete it? He can make a table, but he cannot complete it. There are now two categorical variables, color and gender, but there is not enough information about the girls’ preferences. In addition to the information provided, you need to know how many girls were surveyed or how many prefer red to complete the table. 26. Persevere in Problem Solving Shown are two different tables about a survey involving students. Each survey had a few questions about musical preferences. All students answered all questions. Complete the tables. What type of music do the students prefer? Likes Classical Music © Houghton Mifflin Harcourt Publishing Company Gender Total Girl 21 28 49 Boy 29 22 51 Total 50 50 100 Gender Yes No Girl 34 15 49 Total Boy 36 15 51 Total 70 30 100 All students answered all the questions, so total girls in both is 49, and the total students in both is 100. Overall, the students prefer blues music: 70 students like blues, 50 like classical. IN1_MNLESE389755_U4M08L1.indd 357 Lesson 8.1 No Likes Blues Music Module 8 357 Yes 357 Lesson 1 01/04/14 8:57 PM Lesson Performance Task HARDBOUND SE PAGE 290 BEGINS HERE Two hundred students were asked about their favorite sport. Of the 200 students surveyed, 98 were female. Some of the results are shown in the following two-way frequency table. Favorite Sport Gender Football Baseball Basketball Soccer Female 26 Male 38 Total 64 Total 24 36 12 98 19 21 24 102 43 57 36 200 a. Complete the table. Total number of males: 200 - 98 = 102 Females who chose football: 64 - 38 = 26 Females who chose baseball: 98 - 26 - 36 - 12 = 24 Males who chose soccer: 36 - 12 = 24 QUESTIONING STRATEGIES In what order would you fill in the empty spaces in the table? Explain why. Possible answer: I would first fill in the numbers given in the text of the problem (200 students in total, and 98 female students). Then I would look for a row or column with only one empty cell, and find the missing number (such as the total number of males, the number of females who chose football, or the number of males who chose soccer). After I fill in those numbers, there would still be other rows and columns with only one empty cell, so I would repeat the process until the table is completed. Males who chose basketball: 102 - 38 - 19 - 24 = 21 Total baseball: 24 + 19 = 43 INTEGRATE MATHEMATICAL PRACTICES Focus on Reasoning MP.2 Discuss with students how the sample of Total basketball: 36 + 21 = 57 b. Which sport is the most popular among the students? Which is the least popular? Explain. Most popular is football; 64 is the greatest total. Least popular is soccer; 36 is the least total. c. students chosen for the survey could have influenced the survey results. For example, consider whether age, country of origin, participation in sports, or other characteristics of survey participants might influence the results. Have students describe a target population for which soccer is likely to be the most popular sport among those surveyed. Which sport is most popular among the females? Which sport is most popular among the males? Explain. © Houghton Mifflin Harcourt Publishing Company Most popular among females is basketball; 36 is the greatest number of choices. Most popular among males is football; 38 is the greatest number of choices. Module 8 358 Lesson 1 EXTENSION ACTIVITY IN1_MNLESE389755_U4M08L1 358 Have students create and conduct a survey of 20 students and then record the results in a two-way frequency table. Students should begin by selecting two categorical variables to record, such as gender and favorite subject, or grade level and music preference. Remind them that quantitative and free-response answers are not appropriate for recording in a frequency table. Encourage students to select a sample of students that is not expected to skew the survey results. Have students share their frequency tables and discuss their findings. 7/25/14 7:44 AM Scoring Rubric 2 points: Student correctly solves the problem and explains his/her reasoning. 1 point: Student shows good understanding of the problem but does not fully solve or explain his/her reasoning. 0 points: Student does not demonstrate understanding of the problem. Two-Way Frequency Tables 358