# True or False, MCQs

Please give one line reasoning so that I understand them.

True or False:

1. The Pearson r is a correlation coefficient appropriate for interval/ratio data.

2. The slope of a line is the change in Y divided by the change in X.

3. The standard error of the estimate is the standard deviation of the errors of prediction.

4. Parametric tests are usually more powerful than their nonparametric analogs.

5. If the correlation coefficient r = .33, one-third of the variability in Y is explained by X.

6. If the slope of the imaginary ellipse that we can draw around the points in a scater diagram is from lower left to upper right, the correlation is negative.

7. In general, the wider the imaginary ellipse that we an draw around the points in a scatter diagram, the weaker the correlation.

Multiple Choice:

1. A correlation coeffecient measures:

a) the degree of relationship between 2 variables

b) the magnitude of the difference between 2 variables

c) the estimated effect size between 2 variables

d) the difference betwen the standard error of the means in two or or more samples.

2. A positive correlation means that

a. the 2 variables are significantly related

b. the 2 variables are significantly not related

c. a high score on one variable is usually associated with a high score on the other

d. a high schore on one variable is usually associated with a low score on the other

e. none of the above

3. A zero correlation means that

a. the 2 variables are significantly related

b. a low score on one variable is usualy associated with a low score on the other

c. a high score on one variable is usually associated with a hgh score on the other

d. a high score on one variable is usually associated with a low score on the other

e. none of the above.

4. If the points in a scater diagram generally tended from lower left to upper right, you would conclude that the correlation was probably

a. positive

b. negative

c. zero or close to zero

5. If it is impossible to determine whether the points in a scatter diagram tend from lower right to upper left or from upper right to lower left, the correlation is probably

a. positive

b. negative

c. zero or close to zero

6. Which of the following values for a correlation coefficient would indicate the strongest degree of relationship?

a. -.69

b. -35

c. +.03

d. +.59

7. _____ is the appropriate correlation coeffecient for interval/ratio data; _____ is the appropriate correlation coeffecient for ordinal data.

a. Pearson's r / Spearman's rs

b. Spearman's rs/ Pearson's r

c. Pearson's r / no statistic

d. Spearman's rs/ no statistic

8. There are 2 kinds of nonparametric tests, those _____ and those _____.

a. based on inferences, based on statistics

b. based on order, not based on order

c. based on statistics, based on inferences

d. based on parameters, based on pluralism

9. What type of test is used to determine if the shape of a distribution depends on te value of another variable?

a. THe test of independence

b. THe test of the null hypothesis

c. The test of dependence

d. The test of variable overlap

10. The slope of a straight line is defined as

a. the change in X divided y the change in Y

b. the change in Y divided by the change in X

c. the value of Y when X = 0

d. the value of X when Y = 0

11. THe intercept of a straight line is defined as

a. the change in X divided by the change in Y

b. the change in Y divided by the change in X

c. the value of Y when X = 0

d. the value of X when Y= 0

https://brainmass.com/statistics/nonparametric-tests/true-or-false-mcqs-326258

#### Solution Summary

Complete, Neat and Correct Solutions are provided in the attached file.

Statistics - True and False

1. Degrees of freedom for the independent-measures t statistic can be computed as df = n 1 + n 2 - 2.

True

False

2. For an independent-measures study comparing two samples with n = 8 in each sample, the t statistic would have df = 15.

True

False

3. Which of the following research situations would be most likely to use an independent-measures design?

Compare the blood-pressure readings before medication and after medication for a group a patients with high blood pressure.

Examine the long-term effectiveness of a stop-smoking treatment by interviewing subjects 2 months and 6 months after the treatment ends.

Examine the development of vocabulary as a group of children mature from age 2 to age 3.

Compare the mathematics skills for 9th grade boys versus 9th grade girls.

4. The null hypothesis for the independent-measures t test states

M 1 - M 2 = 0

ì 1 - ì 2 = 0

ì 1 - ì 2 0

M 1 - M 2 0

5. In an independent-measures t hypothesis test, how is the t statistic related to the amount of difference between the two sample means?

The larger the difference between means, the larger the value for t (farther from zero).

The magnitude of the t statistic is not related to the mean difference between samples.

The larger the difference between means, the smaller the value for t (closer to zero).

6. A researcher reports df = 18 for a repeated-measures t statistic. This research study used a total of n = 19 participants.

True

False

7. If a treatment has a consistent effect, then the sample of difference scores will have a small value for variance.

True

False

8. As the size of the difference scores increases, the value of the t statistic decreases (moves closer to zero).

True

False

9. A repeated-measures test usually is more likely to detect a real treatment effect than an independent-measures test because the repeated-measures design reduces the variance and standard error by removing individual differences.

True

False

10. One concern with a repeated-measures design is that a participant's performance in one treatment condition may be influenced by previous experience in another treatment condition.

True

False