Introduction to Statistics

1
Introduction to Statistics

• Lecture Notes
• November 14, 2007
• Dr. Sinn

2
Deciding which test to run, I

• Researchers use a test called the MLA to
  determine the foreign language skills of
  non-native speakers. A university offering a
  Spanish class for high school foreign language
  teachers administers the MLA to their 19 students
  in a standard pre-test/post-test format. Which
  statistical procedure is most appropriate?
• t-interval
• 1 sample t-test
• dependent samples t-test
• Independent samples t-test
• Never use t, always use z cuz its better

3
Deciding which test to run, II

• A sorority is gathering information on apartments
  near the NGCSU campus. They price 20 2-Bedroom
  apartments, run 1-Var Stats on their TI-83
  calculators and then estimate with a 95 level of
  confidence using this data. Which statistical
  procedure is most appropriate?
• t-interval
• 1 sample t-test
• dependent samples t-test
• Independent samples t-test

4
Deciding which test to run, III

• An analyst for a chain of retail stores wishes to
  see how this Christmas buying season compares to
  last year. The early December sales figures of
  50 stores from 2002 are compared with this years
  sales in the same 50 stores. Which statistical
  procedure is most appropriate?
• t-interval
• 1 sample t-test
• dependent samples t-test
• Independent samples t-test
• Never use t, always use z cuz its better

5
Deciding which test to run, IV

• The Survey of Study Habits and Attitudes (SSHA)
  is a psychological test that measures the
  motivation, attitude toward school, and study
  habits of students. A researcher who suspects
  non-traditional students have better attitudes
  toward school gives the SSHA to 20 students who
  are at least 30 years of age. Which statistical
  procedure is most appropriate?
• t-interval
• 1 sample t-test
• dependent samples t-test
• Independent samples t-test

6
Deciding which test to run, V

• Researchers claim that increasing calcium intake
  will reduce high blood pressure. They randomly
  select two groups of Black males. One group
  makes no dietary changes while the other takes a
  calcium supplement. Means are then compared.
  Which statistical procedure is most appropriate?
• t-interval
• 1 sample t-test
• dependent samples t-test
• Independent samples t-test