Choosing the Correct Analysis

1
Choosing the Correct Analysis

• Practice Problems

2
Guidelines

• First ask how many groups?
• Then what type of data?
• If binary, summarized by a proportion.
• If measurement, summarized by a mean.
• Then what research question?
• If is there a difference?, hypothesis testing.
• If how much of a difference?, then confidence
  interval estimation.

3
Question 1

• What percentage of Penn State students smoke
  cigars?

4
Question 2

• Do seniors earn higher semester grade point
  averages than freshmen?

5
Question 3

• What is the relationship between amount of
  alcohol consumed (in ounces) and level of
  coordination (on a scale from 1 to 10)?

6
Question 4

• Is there a difference in the percentage of NCAA
  football players who graduate and NCAA basketball
  players who graduate?

7
Question 5

• Are number of skipped classes and students
  current course grade linearly related?

8
Question 6

• Do a higher percentage of Alaskans commit suicide
  than non-Alaskans?

9
Question 7

• How many hours per week do PSU students study
  outside of class?

10
Question 8

• Do PSU students drink, on average, more than 1
  cup of coffee per day during finals week?
  (During finals week, a sample of students will
  record how many cups of coffee they drink each
  day.)

11
Question 9

• How much more prevalent is lupus in women than in
  men?

12
Question 10

• Is there a relationship between political
  affiliation (Democrat and Republican) and number
  of times voted in past ten years?

13
Question 11

• How much heavier (in pounds) are 15-year old boys
  than 13-year old boys?

14
Question 12

• Is there a relationship between age and ability
  to recall a simple list? A sample of 100 people
  were divided up into two groups (less than 45, at
  least 45). Each person was told a list of 10
  items. The number of items the person was able
  to recall after one minute was recorded.

15
Question 13

• Do Goodyear tires have better tread wear than
  Firestone tires? Tread wear is measured in
  millimeters of tread remaining after 30,000
  miles. Thirty cars are selected for experiment.
  On each car, one Goodyear tire and one Firestone
  tire is placed randomly in one of two front
  positions.

16
Question 14

• A random sample of 64 students were asked Do
  you study regularly at Pattee? The data were
  entered into a Minitab worksheet, as a 1 if
  student said yes and 2 if student said no.
  What statistical procedure would allow us to make
  a statement about students study habits?

17
Question 15

• To what extent are male students heavier than
  female students?

18
Question 16

• How many times each semester do Penn State
  students go home?