Extra Practice - Business Decision Making - ثاني ثانوي

وزارة التعليم Ministry of Education 2024-1446 Business Decision Making S1 S2 S3.indb 343 Extra Practice 1. Suppose that the student council at a Saudi university with 15,000 students is interested in the proportion of students who favor a change in the grading sys- tem to allow for plus and minus grades (for example, B+, B, B-, rather than just B). 200 students are interviewed to determine their attitude about this proposed change. a. What is the population of interest? b. What group of students constitutes the sample in this problem? 2. Classify each of the following variables as either categorical or numerical. For those that are numerical, determine whether they are discrete or continuous. a. birth order classification (only child, firstborn, middle child, lastborn) of a student b. brand of computer purchased by a customer Using Data to Support the Decision Making Process 343 30/06/2023 14:28

344 9 Chapter رة ا Ministry of Education 2024-1446 Business Decision Making S1 S2 S3.indb 344 c. the number of kernels in a bag of microwave popcorn that have not popped after three minutes of cooking 3. A university research team published a report titled "Technical Review of Plagiarism Detection Software". The authors of this report asked faculty at academic institu- tions about the extent to which they agreed with the statement "Plagiarism is a significant problem in academic institutions." The responses are summarized in the accompanying table. Construct a bar chart for these data. Response Frequency Strongly disagree Disagree Not sure Agree 5 48 0 140 39 Strongly agree 4. Many adolescent boys aspire to be professional athletes. The paper "Why Adolescent Boys Dream of Becoming Professional Athletes" (Psychological Reports [1999]:1075–1085) examined some of the reasons. Each boy in a sample of teen- age boys was asked the following question: "Previous studies have shown that more teenage boys say that they are considering becoming professional athletes than any other occupation. In your opinion, why do these boys want to become professional athletes?" The resulting data are shown in the following table: Response Frequency Fame and recognition 94 Money 56 Competitiveness 29 Like sports 27 Easy life 24 Don't need education 19 Other 19 Construct a bar chart to display these data. 30/06/2023 14:28

وزارة التعليم Ministry of Education 2024-1446 Business Decision Making S1 S2 S3.indb 345 5. A psychologist recommends that if you feel the need to check your e-mail in the middle of a movie or if you sleep with your cell phone next to your bed, it might be time to "power off" (AARP Bulletin, September 2010). Suppose that you want to learn about the proportion of students at your school who would feel the need to check e-mail during the middle of a movie and that you have access to a list of all students enrolled at your school. Describe how you would use this list to select a simple random sam- ple of 100 students. 6. For each of the situations described below, state whether the sampling procedure is simple random sampling, stratified random sampling, cluster sampling, system- atic sampling, or convenience sampling: a. To obtain a sample of students, faculty, and staff at a university, a researcher randomly selects 50 faculty members from a list of faculty members, 100 students from a list of students, and 30 staff members from a list of staff. b. A university researcher obtains a sample of students at his university by using the 85 students enrolled in his Accounting class. Using Data to Support the Decision Making Process 345 30/06/2023 14:28

346 9 Chapter رة ا Ministry of Education 2024-1446 Business Decision Making S1 S2 S3.indb 346 7. A report published the circulation numbers for 15 major international news mag- azines as follows: 3,284,012 1,469,223 1,214,590 1,046,977 993,04 931,228 905,755 843,914 783,353 574,370 483,360 412,062 147,808 119,297 41,518 Explain why the average may not be the best measure of a typical value for this data set. Quick Challenge 1. Descriptive statistics is the study of a sample that enables us to make projections or estimates about the population from which the sample is drawn (T or F)? 2. A population is typically a very large collection of individuals or objects about which we desire information (T or F)? 3. A representative sample is a sample obtained in such a way that all individuals had an equal chance of being selected (T or F)? 4. A statistic is the calculated measure of some characteristic of a population (T or F)? 5. The "number of rotten apples per shipping crate" is an example of a categorical variable (T or F)? 6. Classify each of the following variables as nominal, ordinal, discrete, or continuous: a. method of payment for purchases (cash, credit card, check) 30/06/2023 14:28

وزارة التعليم Ministry of Education 2024-1446 Business Decision Making S1 S2 S3.indb 347 b. customer satisfaction (very satisfied, satisfied, not satisfied) c. amount of a purchase d. number of items purchased e. student's identification number 7. The mean checkout time for all customers at a local grocery store in Riyadh is to be estimated by using the mean checkout time for 75 randomly selected customers. Match the items with the statistical terms in the columns below: Data value Data the 75 customers the mean time for all customers Experiment two minutes, one customer's checkout time Parameter the mean time for the 75 customers Population all customers at Corner Convenience Store Sample the checkout time for each customer Statistic the 75 checkout times Variable the process used to select 75 customers and measure their times Critical Thinking A "meaningful paragraph" is a coherent piece of writing in an appropriate con- text that uses all of the listed words. The paragraph should show that you under- stand the meanings of the terms and their relationships to one another. A sequence of sentences that just defines the terms is not a meaningful paragraph. When choosing a context, think carefully about the terms you need to use. Choosing a good context will make writing a meaningful paragraph easier. Using Data to Support the Decision Making Process 347 30/06/2023 14:28

348 9 Chapter رة ا Ministry of Education 2024-1446 Business Decision Making S1 S2 S3.indb 348 Write a meaningful paragraph that includes the following six terms: sample, population, descriptive statistics, bar chart, numerical variable, and dot plot. 30/06/2023 14:28