In the space below, create a table (you can do this using Work\'s built in tools
ID: 3305013 • Letter: I
Question
In the space below, create a table (you can do this using Work's built in tools to create in Excel or copy over) of each variable in the dataset and specify the type and subtype of data that variable is (e.g., a student's gender is categorical, nominal). 1. VariableType (Sub-type) Variable Type (Sub-type Make Model MPG Cylinders Displacement Horsepower Weight Acceleration Year 2. Create an appropriate graph for Make. Explain why this is an appropriate choice. a. What other possible graphs could you have made?Explanation / Answer
1. A categorical variable is classified into categories and a quantitative variable takes numerical value. Note in categorical variables, no mathematical operations can be performed, except counting and comparing sizes, but quantitatve variables are eligible to matematical operations like addition,subtraction, multiplication etc. Thus, the variables Make, Model, year are categorical and the rest are quantitative. Sub type denote the level of measurement for the variables. The nominal level of measurement classifies the variable into categories. Hence, Make, Model and Year have Nominal sub type. MPG, Cylinder, Displacement, Horsepower, Weight and Acceleration are all interval-ratio subtype, as they can be classified into categories, and ranking can also be done on the categories, plus scores can be described in terms of equal units, with a meaningful absolute zero.
2. For categorical varaibel Make, bar chart gives a straighforward visual representation. The categories of variables are arrayed along the horizontal axis (abscissa) and frequencies or percentages (whatever is calculated) is determined along y axis (or ordinate). The heights of the bars are proportional to the relative frequencies of the categories. This is an appropriate choice as bar chart is suitable for any level of meausrement, but is most used in case of nominal level of meaurement.
a. The other possible graph would have been pie chart, which is also an excellent way of displaying the relative sizes of the categories of a variable. The pie chart divides a circle into slices proportional to relative frequencies of the categories. But as pie chart represent parts of a whole the percentage of each categories under the variable, the total percentage has to be 100.