Statistics Midterm 1 Review Flashcards

Vocabulary and terminology from the Math B22L Midterm 1 practice problems, covering data types, levels of measurement, sampling techniques, and statistical visualizations.

Qualitative data

Data that consists of attributes, characteristics, or non-numerical entries.

Sample

A subset or a part of a population used in a study.

Nominal level of measurement

Data that consist of names, labels, or qualities, such as Social security numbers, where no mathematical computations can be made.

Ordinal level of measurement

Data that can be arranged in order or ranked, but the differences between data entries are not meaningful, such as video game ratings.

Interval level of measurement

Data that can be ordered and meaningful differences can be calculated, but a zero entry does not represent "none," such as the average temperature of Bakersfield, CA.

Ratio level of measurement

Data that can be ordered, differences are meaningful, and there is an inherent zero that represents a total absence of a quantity, such as the amount of money in a retirement account.

Systematic sampling

A sampling technique where every $n^{th}$ member of the population is selected, such as studying every $5^{th}$ person that comes to the gym.

Simple random sampling

A sampling technique where every possible subgroup of the same size has the same chance of being chosen, such as selecting one subgroup from all possible $30$-person subgroups of $300$ potential jurors.

Stratified sampling

A sampling technique where the population is divided into groups and a proportional number of subjects are randomly selected from each group, such as asking students from each major about working while in college.

Convenience sampling

A sampling technique that consists only of available or easy-to-reach members of the population, such as surveying coworkers about political opinions.

Confounding variables

Factors that occur when an experimenter cannot tell the difference between the effects of different factors on a variable, often seen in biased studies like a $2:30\,\text{am}$ insomnia survey.

Frequency distribution

A table that shows classes or intervals of data entries with a count or frequency of the number of entries in each class.

Lower class limit

The smallest value that can belong to a specific class in a frequency distribution.

Histogram

A bar graph that represents the frequency distribution of a data set, used to identify the shape of the data.

Box-and-whisker plot

A graph that displays the five-number summary of a data set, including the minimum, $Q1$, median, $Q3$, and maximum.

Standard deviation

A measure of how much the data values deviate from the arithmetic mean, such as $\$3,963$ for Middle City or $\$15,279$ for Richville.

Relatively higher income

The value that has a higher standard score ($z$-score) when comparing data points from different populations, such as comparing $\$75,400$ in Middle City and $\$135,000$ in Richville.