Assignment 1

1. (Please read Faraway (2006 or 2016), Chapter 1 before you do the assignment) The mtcars data was extracted from the 1974 Motor Trend US magazine, and comprises fuel consumption and 10 aspects of automobile design and performance for 32 automobiles (1973-1974 models). The data has 32 observations on 11 variables. The variables are:

   mpg: Miles/(US) gallon

   cyl: Number of cylinders

   disp: Displacement (cubic inches)

   hp: Gross horsepower

   drat: Rear axle ratio

   wt: Weight (1000 lbs)

   qsec: 1/4 mile time

   vs: Engine (0=V-shaped, 1=straight)

   am: Transmission (0=automatic, 1=manual)

   gear: Number of forward gears

   carb: Number of carburetors

   Use mpg as the response and the other variables as explanatory variables to perform a data analysis. Your data analysis should consist of:

   1. an initial data analysis that explores the numerical and graphical characteristics of the data

   2. an exploration of transformations to improve the fit of the model

   3. diagnostics to check the assumptions of your model

   4. some predictions of future observations for interesting values of the predictors

   5. an interpretation of the meaning of the model (parameters) with respect to the particular area of application

   Notice that there is always some freedom in deciding which method to use, in what order to apply them, and how to interpret the results. So, there may not be one clear right answer, and good analysts may come up with different models.

2. In the following examples, distinguish between response and explanatory variables.
   1. Workplace environment; job satisfaction.
   2. Age, resting heart rate; exercise frequency.
   3. BMI; age, gender, hours of screen time per day, physical activity level.
   4. Type of business; location; annual profit; advertising budget; number of employees.
3. Identify each variable as nominal, ordinal, or interval
   1. Favorite type of cuisine (Italian, Chinese, Mexican, Indian, other)
   2. Ranking of favorite sports (1st, 2nd, 3rd, etc.)
   3. Method of payment (cash, credit card, mobile payment, other)
   4. Number of books read in a month (in whole numbers)
   5. Clothing size (XS, S, M, L, XL)
   6. Preferred vacation type (beach, mountain, city, countryside)
   7. Emotional intensity of music (Soft music, classical music, Jazz, Rock, Heavy metal)
   8. Type of weather (sunny, rainy, snowy, cloudy, other)