1. Techniques used to organize, summarize and present data that have been collected are called A. descriptive statistics B. inferential statistics C. Sample D. population 2. The collection of all possible individuals, objects, or measurements is called A. a sample B. population C. an inference D. data 3. Techniques used to determine something about a population, based on a sample, are called A. descriptive statistics B. inferential statistics C. Sample D. population 4. Harry works for a computer company. His job is to make sure that people in their target market, all individuals between the ages of 18 and 54, like their commercials. To test one commercial, he interviews 50 people who are between the ages of 18 and 54, live in Toronto and asks them what they like and dislike about the commercial. What is his population and his sample? A. individuals between the ages of 18 and 54, 50 people who are between the ages of 18 and 54 and live in Toronto B. all individuals, individuals between the ages of 18 and 54 C. 50 people who are between the ages of 18 and 54 who live in Toronto, individuals between the ages of 18 and 54 D. all individuals, 50 people who are between the ages of 18 and 54 who live in Toronto E. individuals between the ages of 18 and 54, 50 people who live in Toronto 5. The mean time for business students who use Internet in Ryerson University (we assume that students in Ryerson as a population) is an example of A. a statistic B. a sample C. a parameter 6. What do we call for the numerical characteristics of a sample? A. statistic B. sample C. parameter Fall2012 Page #1
7. Appearance is very important to professionals working on Bay Street, and most of them do not mind how much they spend on skin care products. From a recent survey, we can conclude that male professionals on Bay Street spend 5% of their salary on skin care products. This is an example of A. descriptive statistics B. inferential statistics C. a sample D. population 8. Due to the outcome of the survey mentioned above, most skin care products companies started advertising in order to attract more male professionals working on Bay Street. After six months of intensive promotional campaign, one company wants to find out whether sales have changed and conducted a data- based research. Identify the population for this research. A. All male professionals on Bay Street B. All male students in Ryerson University C. All female and male professionals on Bay Street D. All working males in Canada 9. What do we call for the numerical characteristics of a population? A. statistic B. sample C. parameter 10. is a portion, or part of the population of interest. A. Statistic B. Sample C. Parameter 11. The main purpose of descriptive statistics is to: A. Summarize data in a useful and informative manner B. Make inferences about a population C. Determine whether the data adequately represents the population D. Gather or collect data E. To predict the future market 12. Which word is NOT a part of the definition of descriptive statistics? A. Organizing B. Analyzing C. Presenting D. Predicting E. None of the above 13. If unemployment is 8.6% of the population in Canada, what is this level of measurement? Fall2012 Page #2
14. What level of measurement is the Centigrade temperature scale? 15. What level of measurement is the number of auto accidents reported in GTA in a given month? 16.The names of the positions on a hockey team, such as forward and defence, are examples of what level of measurement? 17.What level of measurement is the price of an admission ticket to a movie theater in downtown Toronto? 18. The income of a group of 200 loan applicants is obtained. Which level of measurement is income? 19. Ryerson Bank asks customers to evaluate the drive-thru service as excellent, good, average, poor, or very poor. Which level of measurement is this classification? 20. Ryerson Bank conducted a survey of a random sample of its customers. One of the question on the survey was as follows and the possible responses for the question are given The staff at a local branch can provide me with good advice on my financial affairs. (select one) 1. Strongly agree; 2. Agree; 3. Neither agree nor disagree; 4. Disagree; 5. Strongly disagree. What is the measurement scale of the response data? Fall2012 Page #3
21. What level of measurement is a bar code? 22. A group of professional men working at Bay Street tried six brands of hairspray and ranked them according to their preference. What level of measurement is this? 23. A questionnaire contained a question regarding marital status. The responses were checked either single, married, divorced, separated or widowed. What is the scale of measurement for this question? 24. The Equal Employment Opportunity Act requires employers to classify their employees by gender and national origin. Which level of measurement is this? 25. When TV advertisements report, 9 out of 10 dentists surveyed indicated they would recommend Brand X toothpaste to their patients, an informed consumer may question the conclusion because: A. The results were incorrectly computed. B. The conclusion is not illustrated with a graph C. Dentists were not really surveyed. D. The conclusion does not include the total number of dentists surveyed. 26. The following question was asked in a survey conducted by a financial consultant. The possible responses for the question are given. Do you make maximum RRSP contribution within the first four months of the year? Yes No What is the measurement scale of the response data? Fall2012 Page #4
Quantitative Data can be organized into a. Stem-and-Leaf b. Array a. Stem-and-Leaf Each numerical value divides into two parts. The leading digit(s) becomes the stem and the trailing digit the leaf. The stems are located along the vertical axis, and the leaf values are stacked against each other along the horizontal axis. Rules and Conventions Stems: i. Should be from 6 to 13 stems ii. Should be consecutive numbers or repeated numbers. The number may be repeated twice or 5 times. iii. Units must be indicated if stem not to be taken at face value iv. At least one leaf associated with the first and last stem Leaves: i. The leaf for each value is the next single digit after the stem When the stems are repeated twice, the leaves 0-4 go with the first stem and the leaves 5-9 go with the second When the stems are repeated 5 times, the leaves 0-1 go with the first stem 2-3 with the second, etc ii. There is no rounding off iii. They are written in ascending order iv. They must be evenly spaced v. No commas or dashes between the numbers are allowed b. Array 1. Arrange the data in ascending or descending order 2. Advantages a. Identify the lowest and the highest value easily. (range) b. Identify the most frequently occurring value easily. (mode) c. Identify the central value easily. (median) Fall2012 Page #5
Example1: The manager of ABC Liquor Store in downtown Toronto gathered the following information on the number of times a customer visited the ABC Liquor Store during the past six months. The responses of 30 customers were: 17, 28, 16, 18, 58, 45, 44, 43, 76, 73, 57, 92, 97, 42, 66, 69, 44, 57, 62, 62, 97, 76, 12, 13, 71, 21, 6, 9, 7, 9 a. Construct: Stem-and-Leaf b. Arrange the data in the form of an array i. The Stem-and-Leaf Display shows the number of times each customer visited the ABC Liquor Store during the past six months. 0 1 2 3 4 5 6 7 8 9 Fall2012 Page #6
Example2 Given the following data 74 79 64 65 77 75 77 79 78 65 66 76 68 69 75 78 Construct a stem-and-leaf to display the above information Example3 Given the following data. -42, 27, -8, -4, 3, 2, 33, -26, 38, 4, 4, -11, -37, -28, 37, 9, - 41, -43, -44, -47 Construct a stem-and-leaf to display the above information Fall2012 Page #7
Example4 Given the following data. -30-32 5 9-34 -26-21 -27 8-8 -2-7 -6-9 -1-33 -32-26 -12-18 Construct a stem-and-leaf to display the above information Example5 Suppose a survey of employees for a certain department of a certain company reveal that they paid the following amounts of income taxes last year. $20130 $20161 $20207 $20175 $20213 $20147 $20189 $20125 $20264 $20219 $20252 $20173 $20209 $20155 $20128 $20312 $20364 $20389 Fall2012 Page #8
Example6 Suppose a survey of employees for a certain department of a certain company reveal that they paid the following amounts of income taxes last year. $20130 $20161 $20207 $20175 $20213 $20147 $20189 $20125 $20264 $20219 $20252 $20173 $20509 $20685 $20358 $20512 $20694 $20673 Fall2012 Page #9
Example7 Given the following data. -4.28, 2.79, -1.83, -4.73, 3.97, 2.63, 3.38, -2.67, 4.21, -0.11, -0.37, -2.18, 0.07, 3.99, - 3.09, -2.99 Construct a stem-and-leaf to display the above information Fall2012 Page #10