## Instructions

General instructions: You will have an hour (60 min) to complete this exam. Once you have started the clock with start. In other words, it will not save for you. I am expecting that you have spent the normal time preparing for this exam as you would have for an in-class exam.

Multiple choice: You should not treat this as an open book exam as looking up the answers will leave you without enough time to complete it.

### Attempt History

Attempt Time Score Attempt 1 51 minutes 40 out of 46
Correct answers are no longer available.
Score for this quiz: 40 out of 46
Submitted Feb 17 at 8:40pm
This attempt took 51 minutes.

Question 1

/ 2 pts
In the equation for a regression line, the slope is:

the value for X when Y is equal to 0.

the predicted value for Y when X is equal to 0.

the amount that Y is predicted to increase for a 1-unit increase in X.

the z score of the amount that Y is predicted to increase as X increases.

Question 2

/ 2 pts
 Data from 1995 from over 1,000 colleges were used to predict the percent of alumni who donate to a college from the average SAT score of students attending that college. The resulting regression equation was Y = –29.29 + .05(X). This regression indicates that:

for every 1 point increase in SAT scores, a college can expect to get a 29.29% decrease in alumni donating.

for every 1 point increase in SAT scores, a college can expect to get 0.05% increase in alumni donating.

for every 1 dollar increase in donations, the college can expect a half point increase in SAT scores.

for every 1 point increase in SAT scores, a college can expect 0.05% decrease in alumni donating.

Question 3

/ 2 pts
The standard error of the estimate indicates:

how far two regression lines are from each other.

how far the regression line is, on average, from the mean.

how much error there is in any single prediction we make from a given regression equation.

the typical distance between the regression line and each of the observed data points.

Question 4

/ 2 pts

Which of the following statistics quantifies the improvement in our ability to predict a person’s score when using the regression line rather than the mean? Or more specifically, what statistic tells us how much variance in the “DV” is explained by the “IV.”

standard error of the estimation

standard deviation

slope

proportionate reduction in error (or R squared)

Question 5

/ 2 pts

To predict a single outcome variable (a “DV”) from more than one predictor variables (“IVs”), which statistical technique would you use?

multiple regression

structural equation modeling

simple linear regression

correlation

IncorrectQuestion 6

/ 2 pts

If a researcher does not have a good theory to determine which of her three variables (“IVs”)  is the best predictor of the outcome variable (“DV”), which method of multiple regression should she use?

structural equation modeling

hierarchical

stepwise

simple linear

IncorrectQuestion 7

/ 2 pts
Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. They randomly assigned 50 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. What statistical analysis would we perform to answer the researchers’ question?

one-way ANOVA

z test

independent-samples t test

paired-samples t test

IncorrectQuestion 8

/ 2 pts
 It is more difficult to reject the null hypothesis when:

you have a larger as opposed to a smaller sample size.

you have paired-samples t rather than an independent-samples t.

using a two-tailed test rather than a one-tailed test.

None of the above.

Question 9

/ 2 pts
If you have a continuous (e.g., interval) dependent variable and your independent variable is nominal with three or more levels, you could use a(n) ________ to analyze your data.

z test

independent-samples t test

paired-samples t test

ANOVA

Question 10

/ 2 pts
Why can’t a researcher just run multiple t tests when the independent variable has more than two levels?

As you run more statistical tests, it becomes harder and harder to reject the null hypothesis.

As you run more statistical tests, the probability that you will make a Type I error in one of the tests increases.

As you run more statistical tests, you lose degrees of freedom.

As you run more statistical tests, the probability that you will make a Type III error in one of those tests increases.

Question 11

/ 2 pts
The F statistic increases when:

within-groups variance increases.

between-groups variance decreases.

within-groups variance increases and between-groups variance decreases.

within-groups variance decreases and between-groups variance increases.

Question 12

/ 2 pts
A between-subjects design differs from a within-subjects design in that in a between- subjects design

only one group of participants is used.

only variables “between” the participants are examined.

there is a different group of participants for each of the different treatment conditions.

each participant is exposed to each level of the independent variable.

Question 13

/ 2 pts
A measure of the differences among group means is:

the z score.

between-groups variance.

within-groups variance.

the proportionate reduction in error.

Question 14

/ 2 pts
A researcher is conducting an experiment comparing two treatment conditions. If the researcher uses a between-subjects design, there will be _____ score(s) for each participant but if a within-subjects design is used there will be ____ score(s) for each participant.

1, 1

1, 2

2, 1

2, 0

Question 15

/ 4 pts

Suppose I was interested in if people per physician predicts life expectancy. To do so I collect the life expediencies and data on people per physician from Bangladesh, Kenya, North Korea, the United States, and Italy. I find the following means and standard deviations:

Life expectancy: M = 67.70SD = 10.35

People per physician: M = 2957.60SD = 3627.16

I then compute a regression line by doing the following calculations.

Step 1: To find the intercept I set  x = 0

Zx = (0-2957.60)/3627.16 = -.8154

Zy = (-.8154)(-.71) = .5789

Y = (.5789)(10.35) + 67.7 = 73.6916

a = 73.6916

Step 2: To find the slope I set x = 1

Zx = (1-2957.60)/3627.16 = -.8151

Zy = (-.8151)(-.71) = .5787

Y = (.5787)(10.35) + 67.7 = 73.6895

b = 73.6916-73.6916 = -.002

Given my calculations above, what is the regression equation?

Y-hat = -.002 + .73.6916X + ε

Y-hat = 73.6916 – .002X + ε

Y-hat = 67.70 – .002X + ε

Y-hat = -.002X + ε

Question 16

/ 3 pts
Using your answer to question 15 what is the correct interpretation of these data?

As there is a one unit increase in people per physician, life expectancy decreases by .002.

As there is a one unit increase in people per physician, life expectancy increased by 73.6916

As there is a one unit increase in life expectancy, people per physician decreases by .002.

As there is a one unit increase in life expectancy, people per physician increased by 73.6916

Question 17

/ 3 pts
Using your answer to question 15, if people per physician is 100 (x = 100) in Canada then what is the predicted life expectancy for Canadians?

7369.16

73.49

67.50

-.2

Question 18

/ 2 pts

Imagine that your younger brother is convinced that he can predict a person’s age based on the number of movies he or she sees on an annual basis. To do so he measures the number of movies people watch and asks them their age.

What type of analysis should your brother perform to test his idea?

simple linear regression

multiple regression

one-way ANOVA

t-test

Question 19

/ 2 pts

Diana wants to see if eating Valentine’s Day candy causes happiness. She asks 100 participants to come to the laboratory on Valentine’s Day and randomly assigns them to eat a piece of candy or some celery. Participants then spend about 5 minutes rating their levels of general happiness.

What type of analysis should Diana preform in order to test her idea?

simple linear regression

multiple regression

one-way ANOVA

independent-samples t test

Question 20

/ 2 pts

Margo is interested in what reptiles people are most afraid of. To test this she has participants come into the lab and presents them with a snake, a lizard, and a crocodile. After participants see each reptile they rate their level of fear.

What type of analysis should Margo preform in order to test her idea?

simple linear regression

multiple regression

paired-samples t test

one-way ANOVA

Question 21

/ 2 pts
In the question 20 above, what type of design is Margo using?

between-subjects design

within-subjects design

factorial design

correlational design

Quiz Score: 40 out of 46