Mid-quizecurrently.docx

3. Which of the situations below expresses a positive correlation?

The fewer the parasites, the fewer the offspring.

Neither choice is correct. 

The larger the building, the more the cost of upkeep. 

Both choices are correct.

4. When the correlation coefficient is zero, the points on the scatter plot

appear to fall closely to the regression line

appear directly on the regression line

appear randomly scattered on the graph

cannot be plotted

5 Given a correlation coefficient of zero, which conclusion is correct?

A correlation coefficient is not proper for the data.  

Cannot be interpreted.

There is no relationship between the variables.

All of the choices are correct.

6.Whether a correlation coefficient is considered small, medium, or large is a question of

effect size

reliability 

cause and effect

truncation

Your textbook recommends that the first step in working a problem should be to

copy the data;

re-read the problem;

build a database;

estimate the answer.

8. Which of the following words could legitimately fit into this sentence: “That simple frequency distribution has two _________, 13 and 18.”

10. What do you call measurements of a subset of a population? 

What is a graph with a great preponderance of low scores? 

negative skew

positive skew

What is the Mean of the following data set?

100

79

80

59

60

72

47

30

90

95

68

78

72

73

75

14.Which of the following is a paired samples design?

a. At a hunting club the squirrel hunters had a contest with the quail hunters to see who could hit the most moving targets.

b. A consumer-testing group compared Boraxo and Tide to determine which got stuff whiter. Sheets that had been placed for 12 hours in a bathtub of mud were washed and the amount of light reflected was measured with a photometer.

c. Fifth-grade American Indians were matched as a group to a group of New York Puerto Ricans on SES, IQ, and reading level. They were then given a questionnaire on attitudes toward school.

d. On the basis of a pretest on knowledge of foreign governments, each student in the 9:00 class was matched with a student in the 10:30 class. The 9:00 class used a "participant approach" to the study of politics and the 10:30 class used the "Heidleburg method." At the end of the term the same test was given to both classes.

c

a

b

d

15. With an acknowledgment to Sesame Street, "Which of these things is not like the others, which of these things doesn't belong?"

independent samples

repeated measures

natural pairs

matched pairs

16 . Identify the following as paired samples or independent samples. Also give the appropriate df.

Thirteen volunteers weighed themselves before and after a two-day fast.

Paired, df=10 

Paired, df=12

Paired, df=8

Independent, df=12

18. Tukey Honestly Significant Difference test is a(n)          test.

Question 17

A department chair in an academic department wanted to know if there was a difference between spring and fall enrollment in his department.  The department offered the same six courses both semesters. What test should he conduct to determine if there is a significant difference in the enrollment between the semesters?  Write up the results and determine what do the results mean? 

Here is the data set:

Spring

Fall

30

50

35

28

40

30

45

39

50

40

55

25

1