STAT 0200 BASIC APPLIED STATISTICS Fall 2005

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STAT 0200 BASIC APPLIED STATISTICS Fall 2005

• Instructor Prof. Camil Fuchs

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Textbook

• David S. Moore The Basic Practice of
  Statistics, 2000, 3rd ed.

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• Minitab
• Homework will include use of Minitab
• Minitab is available on most of the computers in
  campus
• Minitab can be purchased for 5
• (105 Bellefield Hall, behind Heinz Chapel)

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• Recitations
• Clarification and review of lecture material
• Use of MINITAB
• Quizzes will be administered in recitations
• Individual questions, especially those pertaining
  to the homework assignments
• Recitations this week
• Practice the use of Minitab

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• Requirements
• Homework (10)
• Posted every Thursday on the course Web site
• Hand in recitations of the following week
• You can work together (and encouraged to do so),
  but must hand in separate assignments
• Your worst Homework is not counted

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• Quizzes (15)
• Quizzes will be administered in
  recitations.Quiz schedule
• Quiz 1
• Quiz 2
• Quiz 3
• Quiz 4
• Quiz 5
• One 2-sided sheet of notes is permitted for each
  quiz.

Midterms (15 each) Midterm 1 Wednesday,
October 5, during class time. Midterm 2
Monday, November 21, during class time. One
2-sided sheet of notes is permitted for each
midterm.\ Final (45) Last lecture. Cumulative.
Two 2-sided sheets of notes are permitted.
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• Breakdown of final grade
• 10 HW (worst homework dropped)
• 15 5 quizzes
• 30 midterms
• 45 Final exam
• 100 total

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Help with course material

• Tutoring services free at William Pitt union
• My Office hours by appointment
• E-mail
• TA office hours

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What is statistics?

• Statistics is the science of data
• Design of Collection of Data
• Describing data
• Interpreting data and drawing conclusions
  (inference) from the data collected (sample)
  about the population of interest

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What is Statistics?(and the organization of this
course)

• 1. Collecting data
• Chapter 7,8 producing data, sampling and
  design of experiments
• 2. Describing data
• Chapter 1,2,3 graphical and numerical
  representations of a single variable
• Chapter 4,5,6 describing relations between
  two variables
• 3. Interpreting data and drawing conclusions
• Chapters 13,14,15,16,17,18,19 inference
  methods for means and proportions
• Chapter 20 inference for two-way tables
• Chapter 22 one-way analysis of variance
• 4. Important Statistical models and tools
• Chapters 9,10,11,12 probability, random
  variables and the sampling distribution of the
  mean

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Population all the people or objects that are
of interest to us EXAMPLE - All students that
take statistics courses this semester in USA
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Population
The variable of interest what is the gender
distribution of these students?
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Population
Can not reach all the population
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Population
Sample subgroup of the population
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• Population - The entire group of objects or
  people that are of interest to us.
• All financial firms in New-York
• All the people in Pittsburgh
• All students
• Sample - A subset of the population
• 325 firms that were surveyed
• 1500 people that took an IQ test
• 80 students in this class

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Population
Sample
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Collect data about the sample
Variable of interest gender distribution Ask
each student are you male or female?
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Population all the people or objects that are
of interest to us
Population all the people or objects that are
of interest to us
Inference - infer from sample about population
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Parameter versus Statistic

• Parameter a feature of the population.
• Mean annual income of CEOs.
• Mean IQ of all the people in Pittsburgh
• Percentage of students who wear glasses (out of
  all the students)
• Statistic a numerical measure computed from a
  sample
• Mean annual income of 325 CEOs that are sampled
• Mean IQ in a sample of 1500 people
• Percentage of students who wear glasses in a
  sample of 80 students

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Variable (Categorical and Quantitative)

• A variable is any measurable characteristic that
  varies from one situation to the next. E.g.,
  Gender, height.
• Categorical variable (nominal) a variable whose
  values are categories (e.g., gender, city)
• Quantitative variable variable that is naturally
  numerical (e.g., height, income, market share).
• Discrete comes from a finite or countable set
  of possibilities.
• e.g., number of directors in a firm, shoe
  size
• Continuous comes from an infinite set of
  possibilities
• e.g., weight, time to failure

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Practice What is the type of the variable?

• Salaries of corporate executives __________
• Your telephone number __________
• Record time for 100m dash ___________
• Peoples birth state __________
• Daily low temperatures ___________
• Birth years _____________

Quantitative (cont.)
Categorical
Quantitative (cont.)
Categorical
Quantitative (cont., but reported as discrete)
Quantitative (discrete)
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Describe the data of the sample
Gender Females ___________ Males ___________
Numerical summaries
Graphs... ..\MINITAB
Graphical representations
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Survey

• This survey is anonymous do not write your name.
  
• The answers will be available on the course
  website to be used for homework assignments and
  in class for demonstrating statistical
  principles.
• Please answer all the questions honestly.

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Practice populations, samples, and variables

• A host of a radio talk show announced that she
  wants to know the favorite seafood restaurant
• among city residents. Listeners were asked to
  call and name their favorite seafood restaurant
• Population ________________________________
  ___________________
• Sample _____________________________________
  _________________
• Variable of interest ______________________
  _______________________
• Variable is (i)categorical
  (ii)quantitative-discrete (iii)
  quantitative-continuous
• 2. A survey is carried out in the university to
  estimate the proportion of undergraduates living
  at home during the current term.
• Population _________________________________
  __________________
• Sample _____________________________________
  _________________
• Variable of interest _______________________
  ______________________
• Variable is (i)categorical
  (ii)quantitative-discrete (iii)
  quantitative-continuous
• 3. A consumer magazine article asks, HOW SAFE IS
  THE AIR IN AIRPLANES?
• And then says that its study of air quality
  is based on measurements taken on 158 different
• flights of U.S.-based airlines.
• Population_________________________________
  __________________
• Sample ____________________________________
  _________________
• Variable of interest_______________________
  __________________________