continuous variable
variable that can assume an uncountable set of values
data set
is a collection of observations on one or more variables
discrete variable
variable that can assume a countable set of values only
is a value of a variable for a single element
qualitative variable
only type of variable that cannot be measured numerically
quantitative variable
only type of variable that can assume numeric values for which arithmetic operations make sense
random sample
sample drawn in such a way that each member of the population has some chance of being included in the sample
all subjects or objects whose characteristics are being studied
representative sample
sample that contains the characteristics of the population as closely as possible
conducting a census means
collecting information from all members of the population
conducting a survey means
collecting information from elements
Time-series data are collected
on the same element for the same variable at different points in time
Under descriptive statistics, we study
the methods for organizing, displaying, and describing data
Under inferential statistics, we study
the methods to make decisions about one or more populations based on sample results
A distribution curve that is right-skewed has
a longer tail on the right side
An outlier influences which of the following summary measures the most?
If a data set is right-skewed with one peak in the histogram, then which of the following is true?
the mean is greater than the median, which is greater than the mode
The value of the third quartile for a data set is 65. This means that
75% of the values in that data set are smaller than 65