1. Explain the difference between
a. A Population and a Sample
1. Explain the difference between
b. A Parameter and a Statistic
1. Explain the difference between
c. Descriptive Statistics and Inferential Statistics
c. Descriptive Statistics are merely used to describe some characteristics of a variable in a sample, without regard for the corresponding population parameter values. Inferential Statistics push it one step further: We make an inference (i.e., a generalization; an assumption) that the population parameter values are probably close to the corresponding sample statistic values.
1. Explain the difference between
d. A Variable of Interest and a Control Variable
2. Suppose you measure a nation’s GNP each quarter for thirty years. Is this an example of a “Cross Sectional” or a “Time Series” data set? Why?
Time Series, since the data are collected across different points in time. One possible thing we can study is how these values have changed across time.
3. Suppose you measure the GNP for 87 countries for the third quarter of 2020. Is this an example of a “Cross Sectional” or a “Time Series” data set? Why?
Cross Sectional, since the data are collected at a single point of time and can be analyzed relative to each country, but not across different time periods.
4. A subscription website catering to people who are business executives conducted a marketing survey and asked the following five questions. Classify each resulting variable as either “Categorical (Qualitative)” or “Quantitative,” and briefly explain why.
a. How many nights did you stay in a hotel the past twelve months?
a. Quantitative. The data is counts of counting or measuring how many nights the person stayed in a hotel.
4. A subscription website catering to people who are business executives conducted a marketing survey and asked the following five questions. Classify each resulting variable as either “Categorical (Qualitative)” or “Quantitative,” and briefly explain why.
b. Where do you purchase books: In a Bookstore, On-Line, or from a Book Club?
b. Categorical. The data consist of one of three category labels.