Introduction to Statistics

1
Introduction to Statistics

• Data
• Statistics
• Population
• Census
• Sample

2
Types of Data

• Parameter vs. Statistic
• Quantitative vs. Qualitative
• Discrete vs. Continuous
• Nominal, Ordinal, Interval, and Ratio

3
Figure 1-1
4
Double the length, width, and height of a cube,
and the volume increases by a factor of eight
Figure 1-2
5
97 yes Should the President have the line
item veto to eliminate waste? 57 yes Should
the President have the line item veto, or not?
6
Would you say that traffic contributes more or
less to air pollution than industry? 45 blamed
traffic, 27 blamed industry
Would you say that industry contributes more or
less to air pollution than traffic? 24 blamed
traffic, 57 blamed industry
7

• Refusals
• Percentages
• Correlation and Causality
• Self-Interest
• Over-Precise Numbers

8
Discussion

• P 17 1. A study showed that truck drivers weigh
  more than adults who do not drive trucks.
  Conclusion Trucks cause people to gain weight.
• P 17 6. After the last national census was
  conducted, the Poughkeepsie Journal ran this
  front-page headline 281,421,906 in America.

9
Discussion

• P 17 8 In an ABC Nightline poll, 186,000
  viewers each paid 50 cents to call a 900
  telephone number with their opinion about keeping
  the United Nations in the United States. The
  results showed that 67 of those who called were
  in favor of moving the United Nations out of the
  United States. Interpret the results by
  identifying what we can conclude about the way
  the general population feels about keeping the
  United Nations in the United States.

10
Discussion

• P 18 11 The Hawaii State Senate held hearings
  when it was considering a law requiring that
  motorcyclists wear helmets. Some motorcyclists
  testified that they had been in crashes in which
  helmets would not have been helpful. Which
  important group was unable to testify?
• P 18 12 The author received a survey from the
  investment firm Merrill Lynch. It was designed
  to gauge his satisfaction as a client, and it had
  specific questions rating the authors personal
  Financial Consultant. The cover letter included
  this statement Your responses are extremely
  valuable to your Financial ConsultantWe will
  share your name and response with your Financial
  Consultant. What is wrong with this survey?

11
Classwork

• P 19 25 Write a survey question that addresses
  a topic of your interest. First word the
  question objectively, then word it to encourage
  responses in one direction, then reword it a
  third time to sway responses in the opposite
  direction.
• You may work with each other, but make sure that
  you indicate who you worked with.