TIM7100 Interpret Basic Concepts of Statistics

TIM7100
Data File 1
Assignment 1
1 Consider the set of all students enrolled in a semester-long statistics course. Suppose you are interested in learning about the current grade point averages (GPAs) of this group.
1 What is the population of interest?
The population of interest all students enrolled in a semester-long statistics course.
2 What is the variable of interest?
The variable of interest is the current grade point averages (GPAs) of the students.
3 Suppose you determine the GPA of every member of the class. Would this represent a population or a sample?
The population of interest is the set of existing units and the sample is a subset of the population units, and so this is a population.
4 Suppose you determine the GPA of 10 members of the class. Would this represent a population or a sample?
The GPA of 10 members of the class is a sample.
2 A researcher argues that US Postal zip codes are quantitative data because they measure location, with low numbers in the east and high numbers in the west. Is she correct? Why or Why not?
Quantitative data are measurements that are recorded on a meaningful numerical scale, while the qualitative data are measurements that are not numerical in nature and may be classified into different categories (Christmann, 2011). She is wrong while the zip codes have numerical values, they are not quantitative: as sum of two zip codes is not meaningful, indicating that are either qualitative or categorical variables. The sum of two zip codes or social security numbers is not meaningful.
3 Colleges and universities require several items of information from prospective students. Classify each of the types of data below as either quantitative or qualitative.
5 High school GPA.
High school GPA is a number that mostly ranges between 0.0 and 4.0 so it is quantitative.
6 High school class rank.
The ranking is not meaningful s so it is qualitative.
7 Applicant’s score on the SAT.
The SAT scores range from 200-800 for the sub scores. Therefore, it is quantitative.
8 Gender of the applicant.
Gender is either male or female. Hence is qualitative.
9 Parents’ income.
Parent's income is a figure such as $55,000 per year. Therefore, it is quantitative.
10 Age of applicant.
Age is a number such as 22 years old. Therefore, it is quantitative.
4 Chemical and manufacturing plants often discharged toxic-waste materials such as DDT prior to its ban in the US in the 1980s into nearby rivers and streams. In the mid-1990s, the US Army Corps of Engineers conducteda study of fish in the Tennessee River (in Alabama) and its three tributary creeks: Flint Creek, Limestone Creek, and Spring Creek. A total of 144 fish were captured and five variables were measured for each fish: Classify each of the five variables measured as quantitative or qualitative.
River/creek where the fish was captured
This is location. Therefore, it is qualitative.
Species (channel catfish, largemouth bass, or smallmouth buffalofish)
These are the categories of fish. Therefore, it is qualitative.
Length (centimeters)
Length is measurable and meaningful. Therefore, it is quantitative.
Weight (grams)
Weight is measurable and...