Transcript Chapter 1 What is Statistics / Microsoft Office PowerPoint 97

What is Statistics?
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Art and Science of dealing with data.
Data: numbers with a context (units)…makes
it informative.
Context engages our background knowledge
and allows us to make judgments about the
significance of the number.
Uses data to gain insight and draw
conclusions.
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Sports
Healthcare professionals.
Public policy, and many different fields of
study.
Managers (efficient crunching of numbers
results in a better bottom line).
Scientists/Engineers
This list could go on and on
1. Producing Data
2. Organizing and Describing Data
3. Chance
4. Inference
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Describes methods for producing data which
can give clear answers to specific questions.
Where the data comes from is important…
Learn how to select samples and design.
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Experiments are very influential in statistics.
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Example – Opinion polls, clinical trials, etc…
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Methods and strategies for exploring,
organizing and describing data.
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Using graphs and numerical summaries.
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Learn how to look at data intelligently.
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Probability
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Variation
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Risk
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Moves beyond the data to draw conclusions.
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Take into account that variation is everywhere
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Conclusions can be uncertain.
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When we talk about data, a big part of stats is
deciding what to measure in order to produce
data that helps answer your questions.
Need a clear objective before collecting data.
Measurements are made on individuals and
organized in variables.
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What do these number mean to you?
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The birth weights of my kids
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The mean nothing without units
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9.6 pounds and 9.0 pounds
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Individuals – the objects described by a set of
data
Ex – people, animals, things
Variable – any characteristic of an individual
Can take different values for different individuals.
Although Statistics deals with numbers. Not all
variables are numerical.
To use Statistics with other (non-numerical)
variables we use counts or percents.
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Quantitative variables – numerical values (you
can perform any type of arithmetic with
these)
Ex – test scores, age, salaries, etc…
Categorical variables – use percents or
counts; places an individual into one or
several groups or categories
Ex – grade level, class, eye color
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Individuals -
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Variables –
◦ Students in class
1. ID (categorical)
2. Grade Level (categorical, not
numerical…Fresh, Soph, Junior, Senior OR
9, 10, 11, 12)
3. Gender (categorical)
4. HR (categorical)
5. Counselor (categorical)
6. Test 1 (numerical/quantitative)
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1. Textbook: Pgs. 7&8 #1-4
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2. Data collection sheet
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3. Celtics examples