# Stats Chap 1 & 2

## Terms

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Uniform or Rectangular Histogram
a histogram with the same frequency for all classes
Class
an interval that includes all the values in a (quantitative) data set that fall within two numbers, the lower and upper limits of the class
Inferential Statistics
collection of methods that help make decisions about a population based on sample results
Cumulative Relative Frequency
cumulative frequency of a class divided by the total number of observations
Class Frequency
the number of values in a data set that belong to a certain class
Percentage
obtained by multiplying the relative frequency of that class or category by 100
Class Width or Size
the difference between the two boundaries of a class
Simple Random Sampling
if all samples of the same size selected from a population have the same chance of being selected, it is called simple random sampling. Such a sample is called a simple random sample.
Cumulative Frequency Distribution
a table that lists the total number of values that fall below the upper boundary of that class
Cross-section Data
data collected on different elements at the same point in time or for the same period of time
Frequency Distribution
a table that lists all the categories or classes and the number of values that belong to each of those categories or classes
Class Midpoint
obtained by dividing the sume of the upper and lower limits (or boundaries) of a class by 2
Quantitative Variable
a variable that can be measured numerically
Relative Frequency
the frequency of a class or category divided by the sum of all frequencies
Data Set
collection of observations or measurements on a variable
Qualitative or Categorical Variable
a variable that cannot assume numerical values but is classified into two or more categories
Bar Graph
a graph made of bars whose heights represent the frequencies of respective categories
Statistics
Group of methods used to collect, analyze, present, and interpret data and to make decisions
Census
a survey that includes all members of a population
Sample Survey
a survey that includes elements of a sample
Histogram
a graph in which classes are marked on the horizontal axis and frequencies, relative frequencies, or percentages are marked on the vertical axis. Bars are adjacent (touching)
Cumulative Frequency
the frequency of a class that includes all values in a data set that fall below the upper boudnary of that class
Representative Sample
a sample that contains the same characteristics as the corresponding population
Population or Target Population
the collection of all elements whose characteristics are being studied
Pie Chart
a circle divided into portions that represent the relative frequencies or percentages of different categories or classes
Outliers or Extreme Values
values that are very small or very large relative to the majority of values in that data set
Raw Data
data recorded in the sequence collected before processing
Discrete Variable
a quantitative variable whose values are countable
Descriptive Statistics
collection of methods for organizing, displaying, and describing data using tables, graphs, and summary measures
Element or Member
a specific subject or object included in a sample or population
Cumulative Percentage
cumulative relative frequency multiplied by 100
Class Boundary
the midpoint of the upper limit of one class and the lower limit of the next class
Time-Series Data
data that give the values of the same variable for the same element at different points in (or for different periods of) time
Symmetrical Histogram
a histogram that is identical on both sides of its central point
Random Sample
a sample drawn in such a way that each element of a population has some chance of being included in the sample
Polygon
a graph formed by joining the midpoints of the tops of successive bars in a histogram by straight lines
Survey
collection of data on the elements of a population or sample
Qualitative or Categorical Data
data generated by a qualitative variable
Ogive
a curve drawn for a cumulative frequency distribution
Grouped Data
a data set presented in the form of a frequency distribution
Variable
a characteristic under study that assumes different values for different elements

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