Exam II

Question 1

Which of the following refers to the group you wish to generalize your results to?

Answer 1

Population

Question 2

Which of the following can be tested directly?

Answer 2

The research hypothesis

Question 3

Which of the following is a directional test?

Answer 3

a one-tailed test

Question 4

In order to help ensure generalizability, which of the following should be true about your sample?

Answer 4

It is large and representative

Question 5

What test would you want to use to test a directional research hypothesis?

Answer 5

One-tailed test

Question 6

Which of the following symbols represents the null hypothesis?

Answer 6

H0

Question 7

When the sample accurately represents the population, the results of the study are said to have a high degree of…

Answer 7

generalizability

Question 8

If you were to hypothesize that test scores from classroom A will be higher than test scores from classroom B, you have a:

Answer 8

Directional research hypothesis

Question 9

What is the foundation of inferential statistics?

Answer 9

Probability

Question 10

The fact that the trails of a normal distribution never touch the horizontal axis relates to the following property:

Answer 10

Asymptotic

Question 11

If you want to calculate a z score for a test where your raw score was 24, what other information must you know?

Answer 11

Mean and standard deviation

Question 12

What percent of all scores fall below a z score of +1?

Answer 12

84%

Question 13

Z-scores which fall below the mean will be:

Answer 13

Negative

Question 14

This percentage of scores fall within three standard deviations of the mean:

Answer 14

99.5%

Question 15

If a distribution has a mean of 30 and a standard deviation of 5, how many standard deviations is 60 from the mean?

Answer 15

6

Question 16

The level of chance or risk that you were willing to take is expressed as…

Answer 16

a significance level

Question 17

When you accept a false null hypothesis, you are making a:

Answer 17

Type II error

Question 18

Which of the following occurs when you accept the null hypothesis when it is really false?

Answer 18

Type II error

Question 19

After you compare the obtained value with the critical value, you:

Answer 19

reject the null hypothesis if the obtained value is more extreme than the critical value

Question 20

A smaller confidence interval would result in:

Answer 20

a smaller range of values in the confidence interval

Question 21

If you want to examine the differences between the average scores of two unrelated groups, which of the following statistical techniques should you select?

Answer 21

Independent samples t-test

Question 22

In order to determine whether or not you will reject the null hypothesis, the test statistic must be compared against the…

Answer 22

critical value

Question 23

A(n)___ difference is due to some systematic influence and due to chance

Answer 23

significant

Question 24

Which major assumption of the t-test deals with the amount of variability in each group?

Answer 24

variances are equal

Question 25

The t-test for independent means is used when you are looking at the difference in average scores of one or more variables between____ groups that are_____of one another.

Answer 25

two, independent

Question 26

In the formula that computes a t-value, what does X1-bar represent?

Answer 26

the mean of group 1

Question 27

In the t-test for independent means, the actual statistical test is

Answer 27

Nondirectional

Question 28

If the obtained value is greater than the critical value, what should you do?

Answer 28

reject the null

Question 29

If one group had a mean of 2.3, and the second group had a mean of 2.4, and this was statistically significant, this result could be described as:

Answer 29

significant and not meaningful

Question 30

If the number of participants in group 1= 54 and the number in group 2 = 58, what is the associated degrees of freedom (for a t-test)

Answer 30

110

Question 31

A measure of how different two groups are from one another is the ____

Answer 31

effect size

Question 32

What is the assumption that the amount of variability in each of the groups is equal?

Answer 32

homogeneity of variance