What are the uses of Statistics in the business world?
To summarize data
to draw conclusions from those data
To make reliable forecasts about business activities
To Improve business processes
Define Descriptive statistics
The methods that help collect, summarize, present, and analyze a set of data
Define Inferential Statistics
The methods that use the data collected from a small group to draw conclusions about a larger group
Define a Variable
A characteristic of an in item or individual
The different values associated with a variable
What are operational definitions
Universally accepted meanings that are clear to all associated with an analysis
Consists of all the items or individuals about which you want to reach conclusions
The portion of a population selected for analysis
A measure that describes a characteristic of a population
What is a Statistic
The measure that describes a characteristic of a sample
Define a categorical variable
Qualitative variable, have values that can only be placed in categories, like yes and no;
What is Numerical variables
Quantitative variable, have values that represent quantities, numerical variables are further identified as being either discrete or continuous variables
What are Discrete variables?
have numerical values that arise from a counting process, ie the number cable channels subscribed to, also the number of items purchased
What is a continuous variable?
Produce numerical values that arise from a measuring process, IE the time you wait
What is a nominal scale?
Classifies data into distinct categories in which no ranking is implied, IE your favorite soft drink, political party, gender, weakest form of measurement
What is an ordinal scale?
Classifies values into distinct categories in which ranking is implied, IE How was your service, poor, good excellent; the ordering implies only which category is 'greater', not by how much
What is an interval scale?
An ordered schale in which the difference between measurements is a meaningful quantity but does not involve a true zero point... such as temperature on the Celsious scale
What is a ratio scale?
an ordered scale in which the difference between the measurements involves a true zero point, height weight, age, or salary
Define a histogram
a bar chart for grouped numerical data in which you use vertical bars to represent the frequencies or percentages in each group. There are no gaps between adjacent bars. The variable of interest along the x axis, and the frequency or the percentage on you y axis
What is a Percentage Polygon?
Uses the midpoints of each class interval to represent the data of each class and then plots the midpoints, at their respective class percentages