Note:
  • The variable type must be one of continuous, discrete, nominal, or ordinal (saying quantitative or categorical is not specific enough).

Types of Variables I

  1. Miles driven per week is quantitative, continuous because another value CAN be found between any two miles driven values (e.g., a student can drive between 10 and 10.1 miles per week, between 10 and 10.01 miles per week, and so on).
  2. Type of vehicle is categorical, nominal because the types represent groups but there is no order among the groups.
  3. Signs of disease is categorical, nominal because “yes” and “no” are groups and a categorical variables with two levels is nominal by definition.
  4. Number of fleas is quantitative, discrete because another value can NOT be found between all pairs of numbers of fleas (e.g., there cannot be between 10 and 11 fleas).
  5. Relative health of a rabbit is categorical, ordinal because the health was organized by groups (e.g., excellent) and those groupings were ordered.
  6. Species of rabbit is categorical, nominal because species is a type of group, but there is no order among those groups.
  7. Number of correct answers is quantitative, discrete because a value can NOT be found between all pairs of correct answers (e.g., there cannot be between 19 and 20 correct answers).
  8. Concentration of lead is quantitative, continuous because a value CAN be found between any pair of lead concentrations.
  9. Risk potential is categorical, ordinal because a grouping was created (e.g., “high risk”) and those groupings have an order.
  10. Information medium is categorical, nominal because they are types, but those types do not have an ordering.
  11. The Koppen scheme is definitely categorical and I think it is nominal because I don’t see an ordering in the given categories (i.e., they don’t appear to range from wet to dry, cold to hot, north to south).


Note:
  • The specificity in the description for the individual (usually specific about “when” and “where”).
  • The use of “ALL” when describing the population and parameter.
  • The list of a specific number of individuals when describing the sample and statistic.
  • The use of a specific type of summary (almost always the mean/average or percentage/proportion) when describing the parameter and statistic. Further note that the same summary word is used for both the parameter and statistic.
  • A summary word usually does not appear in the description of the variable.
  • The variable type must be one of continuous, discrete, nominal, or ordinal (saying quantitative or categorical is not specific enough).

Sustainability Survey

  • I - A Northland College Student in Fall, 2013
  • V - Number of miles driven per week
  • Po - ALL Northland College Students in Fall, 2013
  • Pa - Average number of miles driven per week by ALL Northland College Students in Fall, 2013
  • Sa - 147 sampled Northland College students
  • St - Average number of miles driven per week by 147 sampled Northland College Students in Fall, 2013
  • Variable Type - Miles driven per week is quantitative, continuous because another value can be found been any two miles driven.

Crayfish and Bass

  • I - a Rusty Crayfish in the lake with Smallmouth Bass in 2015
  • V - carapace length of Rusty Crayfish
  • Po -ALL Rusty Crayfish in the lake with Smallmouth Bass in 2015
  • Pa - mean carapace length of ALL Rusty Crayfish in the lake with Smallmouth Bass in 2015
  • Sa - 235 Rusty Crayfish in the lake with Smallmouth Bass in 2015 that were actually examined
  • St - mean carapace length of 235 Rusty Crayfish in the lake with Smallmouth Bass in 2015
  • Variable Type - Carapace length is a continuous quantitative variable because a carapace length can be found between any two carapace lengths.

Types of Variables II

  1. Answers will vary by student. See instructor if you have questions about your example.