Stat243 Week1
Discrete variable
is a quantitative variable for which the possible values are separate values such as 0, 1, 2, ....
Continuous variable
is a quantitative variable for which the possible values form an interval.
Quantitative variables
take numerical values that represent different magnitudes of the variable.
Identify each of the following variables as continuous or discrete. a. Blood sugar level b. The characters typed per minute c. The length of a person's hair d.
a. Blood sugar level is a continuous variable since it has an infinite continuum of possible values b. is a discrete variable since it has a finite number of possible values. c. is a continuous variable since it has an infinite continuum of possible values. d. is a discrete variable since it has a finite number of possible values.
Identify each of the following variables as continuous or discrete. a. The number of questions on a test b. The distance (in miles) between major cities c. The depth of the ocean d. The number of kittens in a litter
a. The number of questions on a test is a count, so its possible values form a set of separate numbers. Thus, the number of questions on a test is a discrete variable. b. The distance between major cities is a physical measurement, so its possible values form an interval. Thus, the distance (in miles) between major cities is a continuous variable. c. The depth of the ocean is a physical measurement, so its possible values form an interval. Thus, the depth of the ocean is a continuous variable. d. The number of kittens in a litter is a count, so its possible values form a set of separate numbers. Thus, the number of kittens in a litter is a discrete variable.
Identify each of the following variables as categorical or quantitative. a. Number of words in an article b. Types of birds seen at a feeder c. Weight loss d. Albums in a collection
a. The number of words in an article allows observations to take on numerical values that represent different magnitudes of the variable. Since the number of words in an article can be counted, we can measure this variable with numbers. Therefore, the number of words in an article is a quantitative variable. b. Types of birds seen allows each observation to belong to one set of categories. Since descriptions of birds can include robins, sparrows, and hummingbirds, we cannot measure this with numerical values. Therefore, types of birds seen at a feeder is a categorical variable. c. Weight loss allows observations to take on numerical values that represent different magnitudes of the variable. Since weight loss can be counted in pounds, we can measure this variable with numbers. Therefore, weight loss is a quantitative variable. d. Albums in a collection allows each observation to belong to one set of categories. Since descriptions of albums can include hard rock, country, and rap, we cannot measure this with numerical values. Therefore, albums in a collection is a categorical variable.
Identify each of the following variables as categorical or quantitative. a. Model car driven b. Noise levels in a city (in decibels) c. Total worth of paintings in a collection d. Dream vacation location
a. is a categorical variable. Its values are not numerical b. Noise levels in a city (in decibels) is a quantitative variable. Its values are numerical. c. is a quantitative variable. Its values are numerical. d. is a categorical variable. Its values are not numerical.
