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1. Explain the two meanings of the word “statistics.” 2. Briefly describe the areas of statistics. 3. Explain the difference between a population and a sample. 4. Explain which of the following constitute a population and which constitute a sample. a. Incomes of 500 families selected from New York b. Salaries of all employees of a company c. Number of absences during the semester for each of the students in a class d. Number of cars owned by each of the 100 families selected from a city e. Color of hair of 25 girls 5.Briefly describe the difference between a quantitative and a qualitative variable. Explain what is meant by discrete and continuous variables. Give one example of each of such variables. 6. Which of the following variables are quantitative and which are qualitative? Classify the quantitative variables as discrete or continuous. a. Weight of a package b. Color of eyes of people c. Price of a concert ticket d. Number of televisions owned by families e. Number of births on a day in a hospital 7. Which of the following variables are quantitative and which are qualitative? Classify the quantitative variables as discrete or continuous. a. Model of a car b. Food expenditure per month for families c. Number of children per family d. Commuting time from home to work for a person e. Number of houses on a block
Solutions 1. The word “statistics” could be referring to numbers or numerical facts, but it could also be referring to the field or discipline of study that surrounds the methods used to collect, analyze, present, and interpret data for decision making. 2. The two major areas of statistics are descriptive and inferential. We use descriptive statistics to organize, display, and describe data by using table, graphs, and summary measures. Inferential statistics use sample results to assist in making predictions or drawing conclusions about a population. 3. A population represents the entire collection of units about which information is sought, whereas a sample is a smaller portion of the population from which measurements are taken in the course of an investigation.
4. a. Sample b. Population c. Population
d. Sample e. Sample
5. Qualitative data describe a particular characteristic of an item and are usually categorical in nature, whereas quantitative data are numerical and usually involve counting or enumerating. Discrete data involve counting or enumerating, and the only possible values are positive integers, whereas data that are continuous can take on any one of an infinite number of possible values over an interval on the number line. The number of parking tickets that people receive each year is discrete. The heights and weights of people is continuous. 6. a. Quantitative, continuous b. Qualitative, continuous c. Quantitative, continuous
d. Quantitative, discrete e. Quantitative, discrete
7. a. Qualitative, discrete b. Quantitative, continuous c. Quantitative, discrete
d. Quantitative, continuous e. Quantitative, discrete
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