Chapter 1 – Introduction and Data Collection
o
Descriptive Statistics
Collects, summarizes and presents data
o
Inferential Statistics
Uses sample data to draw conclusions about an entire population
o
Population
All the items or individuals about which you want to draw a conclusion
o
Parameter
Numerical measure that describes a characteristic of a pop.
o
Sample
Portion of a pop. selected for analysis
Probability Sample
 items in the sample are chosen on the basis of known
probabilities
Nonprobability Sample
items included are chosen w/o regard to their probability
of occurrence
o
Statistic
A numerical measure that describes a characteristic of a sample
Chapter 2 – Presenting Data in Tables and Charts
o
Numerical Data (quantitative, values that represent quantities) DISCRETE & CONTIN.
Ratio(highest level of measurement)
w/ true zero.
Ex. $0 in bank acct means you
really don’t have any money.
0 ft. means nothing is there.
Interval(secondhighest level of measurement)
w/o true zero.
Ex. 0 degrees doesn’t
mean there isn’t any temperature.
0 elevation just mean you’re at sea level.
o
Ordered Array
Sequence of data, in rank order, from smallest to largest value
o
Stem and Leaf Display
Organizes data into groups (stems) so that the values within each group (leaves) branch
out to the right on each row
o
Frequency Distribution summary table in which the data are arranged into numerical
ordered class groupings.
Width of class interval
, divide range of data by # of desired class groupings
Class midpoint,
halfway between the lower boundary and upper boundary of the class.
Ex. Midpoint of $10 and $15 is $12.50
Relative frequency,
divide the frequency of class by total frequency distrib. values
Percentage distribution,
multiply each relative frequency by 100%
o
Frequency Histogram
bar chart for grouped numerical data in which the frequencies or percentages of each
group of data are represented as individual vertical bars
o
Frequency Polygon (used when you have two or more groups of data)
Formed by having the midpoint of each class represent the data in that class and then
connecting the sequence of midpoints at their respective class percentages.
o
Ogive (Cumulative Percentage Polygon)
Displays the variable of interest along the X axis, and the cumulative percentages along
the Y axis
o
Categorical Data (qualitative, values that can only be places into categories)DISCRETE
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Ordinal(secondlowest level of measurement)
w/ rank.
Ex. Fr. So. Jr. Sr.
can be
ranked or ordered
Nominal(lowest level of measurement)
w/o rank.
Ex. Gender, zip codes
can’t rank
or order
o
Summary Table
Indicates the frequency, amount, or percentage of items in a set of categories so that you
can see the differences between the categories
o
Bar Chart
Shows each category, the length of which represents the amount, frequency or percentage
of values falling into a category.
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '07
 Randall
 Statistics, Inferential Statistics, Normal Distribution, Standard Deviation, Cluster Sample Population

Click to edit the document details