QUESTION 1

p < .05 means that the difference between sample means

• the results should be declared “not significant”;
• should be attributed to chance rather than to the independent variable
• both choices are correct
• none of the choices are correct

QUESTION 2

The null hypothesis in a paired samples t test is that the two

• samples have identical means
• populations have different means
• samples have different means
• populations have identical means

QUESTION 3

In an independent samples design, the null hypothesis is that

• the population mean of one group is equal to that of a second group
• the sample mean of one group is equal to that of a second group
• sample mean of one group is larger or smaller than that of a second group
• the population mean of one group is larger or smaller than that of a second group

QUESTION 4

A correlation coefficient of .72 based on 7 pairs is, for a two-tailed test,

a.not significant

b.significant at the .001 level

c.significant at the .05 level

d.significant at the .01 level

5 points

Suppose you obtained a sample from a population different from the one specified by the null hypothesis. On the basis of a t test, you failed to reject the null hypothesis. You have made a

a.Type II error

b.correct decision

c.any of the other alternatives could be; more information is needed

d.Type I error

QUESTION 6

According to your text, the motivation of the agricultural scientists (agronomists) who selected 30:1 as the point separating differences due to chance from those not due to chance, was

a.to maximize the chance that a recommendation to change would be made

b.to minimize a Type II error

c.to minimize the chance of making a false recommendation

d.that tables already existed for odds of 30:1

QUESTION 7

1 – b is the ___ of a statistical test.

a.neither of the descriptive alternatives are correct

b.both of the descriptive alternatives are correct

c.probability of a

d.power

QUESTION 8

Data Set 10-1

A college teacher was assigned 4 freshmen advisees. He administered an attitude scale that measured liberalism-conservatism. Four years later, just before graduation, all 4 took the same scale again. High scores indicate conservative attitude. The following scores were obtained.

Freshman yearSenior year

2615

2223

1714

1510

The proper conclusion for the experiment described in Data Set 10-1 is

a.there was no significant shift in attitudes

b.there was a significant shift in attitudes from conservative to liberal (p < .05)

c.there was a significant shift in attitudes from liberal to conservative (p < .05)

QUESTION 9

Critical values are in the rejection region of the t distribution.

True

False

QUESTION 10

The symbol for an effect size index is ñ (rho).

True

False

QUESTION 11

The numerator of a t test is a difference between means.

True

False

QUESTION 12

If a difference is statistically significant, the null hypothesis was rejected.

True

False

QUESTION 13

The two opposing hypotheses in null hypothesis significance testing are the null hypothesis and the derivative hypothesis.

True

False

SAMPLE ASSIGNMENT

Sample-2