PSY 302 Final

Which of the following correlations reflects the strongest relationship between variables? a) +0.03 b)-0.64 c) +0.49 d) +1.30

-0.64

If the correlation coefficient r = .4 for the relationship between stress and anxiety symptoms, what is the proportion of variance in anxiety that can be explained by stress? A. 0 B. .16 C. .2 D. .4

.16

Given the results r(29) = -.84, p < .05, what is R 2?

.71

A researcher found a correlation between GPA and IQ scores of r = 0.34. What is the proportion of variance in the GPA explained by IQ? Round your answer to two decimal points

0.12

An analysis of student records found that 16% of variability in college GPA is explained by students high-school GPA. What is the correlation r between college GPA and high-school GPA?

0.4

A good regression line... (check all that apply) 1. has the smallest possible residuals. 2. goes right through the middle of the data. 3. has large residuals. 4. a steep slope.

1. has the smallest possible residuals. 2. goes right through the middle of the data.

Let b = -0.09, the mean of x scores = 5.47, and the mean of y scores = 2.01. Calculate the y-intercept for the regression line. Round your answer to 2 decimal places.

2.5

For the following regression equation, what is the expected value of Y if X = -1? Y i ^ = 23.44 − 2.66 X i 1. There is not enough information to answer this question. 2. 20.78 3. 26.10 4. 23.44

26.10

You run a multiple regression model and get the coefficients a=3, b 1= 2.9, and b 2=2.Predict Y when X 1= 8 and X 2 = 8. Round your answer to 2 decimal places.

42.2

We conducted a hypothesis test for the Pearson correlation coefficient r. What are the degrees of freedom when the number of participants from which the r-value was computed was 52?

50

Researchers believe there may be a link between breast feeding and autism. They conducted an online survey and found that out of 100 people who reported being breast fed, 4 were diagnosed with autism. Of the 80 people who reported using a formula as infants, 13 were diagnosed with autism. Calculate the expected frequency for people who were breast fed and have not been diagnosed with autism. For each step in your calculations, round your answers to the nearest hundredth before entering into the next step. Round your final answer to the nearest hundredth.

90.56 I keep getting 45.278 which is 90.56 dived by 2

A psychologist is interested in comparing the demographics of grand jury members to demographics of the population to see if grand jury panels are really representative of the population. The first variable she examines is age. The percentage of people over 65 in the population is 25%, but out of 200 people empaneled for grand jury trials, 76 (38%) were aged 65 or more. She wants to know if the proportion of people over 65 on grand juries is significantly different than that proportion in the population. What test should she use?

Chi-square goodness of fit test

which test: Does the number of syllables influences memory for words? I tried to memorize 50 words. Twenty- five of the words were one-syllable words and 25 are three-syllable words. I remembered 15 of the single-syllable words and 8 of the three-syllable words.

Chi-square test of independence: 1. Nominal variable 1: word length (1syllable, 3syllable) 2. Nominal variable 2: memory (remembered, forgotten) 3.are word length and memory related?

which test: Your GTFs believe that PSY 302 students' favorite statistical test is the z-test. They decide to survey one of the lab sections, asking students to pick their favorite statistical test out of the 11 we've studied. Which test would be used to determine if students prefer some statistical tests more than others?

Cji-square goodness of fit: equal proportion

The most commonly used measure of effect size for independent samples t-test is 1 p-value 2 Cohen's d 3 t-value 4 eta squared

Cohen's d

Regression analysis revealed best fitting regression line Y = 0.29*X + 47 What is the strength of the relationship between X and Y? A.small B.medium C.large D.it cannot be determined based on the information given

D.it cannot be determined based on the information given. Strength of a relationship is determined by the value of r but not b

A researcher assigns participants in a research study to sit, stand, or do jumping jacks while solving difficult math problems. Additionally, participants must do the problems either with or without a calculator. It is unclear what the researcher hopes to learn from this experiment. Which statistical test should the researcher use to see whether body position (sit/stand/jumping jacks) and calculator use affect problem-solving speed?

Factorial ANOVA

Given the following regression equation, interpret the slope. Y i ^ = 23.44 − 2.66 X i 1. For every 2.66 units decrease in X, the model expects a 1 unit increase in Y. 2. For every 1 unit increase in X, the model expects a 2.66 units increase in Y. 3. For every 1 unit increase in X, the model expects a 23.44 units increase in Y. 4. For every 1 unit increase in X, the model expects a 2.66 units decrease in Y.

For every 1 unit increase in X, the model expects a 2.66 units decrease in Y.

A researcher reports that people need eight hours of sleep to function efficiently during the day. In her review she states that 70% of the American population gets less than eight hours of sleep a night, 20% gets eight hours, and 10% gets more than eight hours. You survey 100 college students and find 80% get less than eight hours of sleep a night, 15% get eight hours, and 5% get more than eight hours. How college students' sleep patterns compare to the general public? Which of the following is the appropriate null hypothesis? 1. H0: P = (.7, .2, .1) 2. H0: P = (.33, .33, .33) 3. H0: P = (.25, .25, .25) 4. HA: P = (.7, .2, .1)

H0: P = (.7, .2, .1)

A researcher wants to know whether culture is related to the self-serving bias. She collects data from a group of U.S. students and a group of Chinese students. She has all participants complete a standard self-serving bias questionnaire (using a continuous scale), and tests which culture has a greater self-serving bias. Which test? A)One-sample t-test B)Factorial ANOVA C)Correlation D)Independent-samples t-test

Independent-samples t-test: One continuous measure, 2 groups, different people in each group

Which scenario could be analyzed using a factorial ANOVA? 1 Kai assesses whether experiencing life events is related to distress. 2 Bill tests whether males and females differ on a measure of emotional expressiveness. 3 Samantha examines the effect of anxiety on music performances during a student recital. 4 Kamal measures the impact of noise and task difficulty on a memory task.

Kamal measures the impact of noise and task difficulty on a memory task.

A psychologist wants to investigate the relationship between stress and mental health during the first year of college. The researcher developed scales that measure 1) the frequency of stressful events, 2) the perceived importance of these events, 3) the desirability of such events, and 4) the impact of these events of the student. The researcher had 150 first year college students fill out this questionnaire as well as a Symptom Checklist, which is designed to assess the presence or absence of psychological disorders. What statistical procedure would help this researcher discover if psychological disorders can be predicted from the different aspects of stress that have been measured?

Multiple regression

You are analyzing a data set with multiple continuous predictors and one continuous outcome variable. Which statistical test should you use? 1. Simple regression 2. A t-test 3. Correlation 4. Multiple regression

Multiple regression

What is the expected grade on the final exam for someone who scored 75% on Midterm 2 and spent 8 hours preparing for the exam?

Multiple regression (outcome: grade on final, predictors: grade on Midterm 2 & number of hours spent studying)

what does a one way anova test for

One-way ANOVA tests for a relationship between one categorical variable called a factor (typically with 3 or more levels) and one continuous variable

A researcher believes that recall of verbal material differs with the level of processing. He divided his subjects into three groups. In the low processing group, participants read each word and were instructed to count the number of letters in the word. In the medium processing group, participants were asked to read each word and think of a word that rhymed. In the high processing group, participants were asked to read each word and think about something that happened to them that would relate to that word. Each group was allowed to read the list of 30 words three times, then they were asked to recall as many of the words on the list as possible. If the researcher wants to know whether the three groups have different amounts of recall, what type of statistical test should be used?

One-way between-subjects ANOVA One-way ANOVA can be used to test hypotheses regarding the equality of the means of three or more groups. If after testing your data you found significant differences amongst your groups, you would use a post-hoc technique such as Tukey's test to determine which specific groups performed better than others.

A psychologist is interested in attitudes towards the disabled. She believes that contact with someone who is disabled might have an effect on peoples' attitudes. To test her hypothesis, she measured attitudes toward the disabled both before and after contact with an individual in a wheelchair. What type of statistical test should she use to determine if contact with a disabled person changes peoples' attitudes toward the disabled?

Paired samples t-test

which test: An exercise physiologists wants to predict number of pounds gained between ages 30 and 35 from the number of TV watching hours per week at age 30.

Simple linear regression (keyword: predict)

Which correlation coefficient measures the association between ordinal variables?

Spearman rank-order correlation coefficient

Which variable should you plot on the y-axis? 1. The causal variable, if there is one. 2. The effect (outcome) variable, if there is one. 3. The variable with larger values. 4. There is no convention.

The effect (outcome) variable, if there is one.

When should you NOT use a Pearson correlation to measure the relationship between two variables in your data set? 1. The relationship between the two variables is expected to be linear. 2. The relationship between the two variables is expected to be negative. 3. The relationship between the two variables is expected to be strong. 4. The relationship between the two variables is expected to be quadratic.

The relationship between the two variables is expected to be quadratic.

when do you use a chi-square goodness-of-fit equal proportions test

Use chi-square goodness-of- fit equal proportions when you have count data for each level (category) of a single nominal variable and you want to know if the frequency of response is the same across all categories ex: Are babies equally likely be born every day of the week?

when do you use a chi-square goodness-of-fit comparison test

Use chi-square goodness-of-fit comparison when you have count data for each category of a single nominal variable and you want to know if the frequency of response in the sample is the same as some known proportions ex: Is a similar proportion of UO undergraduates getting a flu shot as the proportion in the USA as a whole (35%)

when do you use a chi-square test for independence test

Use chi-square test for independence when you have count data on two nominal variables and you want to know if the two variables are related/associated with one another ex: Is the relative preference for vanilla vs. chocolate ice-cream different among Americans vs. Europeans?

when do use a correlation test

Use correlation when you measure the same people/objects/units on two different properties (variables) and you want to know if the measurements are associated with (related to) each other and how strongly ex: Is persons weight related to their height? Is car's mileage related to its horsepower? Is mother's years of education related to child's academic success?

when do you use a factorial anova

Use factorial ANOVA when you have more than one factor of interest, each with at least two levels. Factorial ANOVA simultaneously tests whether there is variation due to any of the factors (main effects) or due to the interaction of factors

when do you use a independent samples t-test

Use independent -samples t-test when you have two independent samples and want to know if the populations from which they were drawn have different means

when do you use linear regression

Use linear regression when you measure the same people/objects/units on two different properties (variables) and you want to predict a score on one variable given some score on the other variable ex: Can we predict people's weight from their height? What is a likely mileage of a car with 200 horsepower? What's the most likely grade of a child whose mother has 10 years of education?

when do you use a one-sample t-test

Use one-sample t-test when you have one sample and are comparing it to a population with a known or hypothesized mean, but where population variance is unknown

when do you use a one-way between -subjects anova

Use one-way, between-subjects ANOVA when you have 3 or more independent groups and want to know if there are differences among a set of population means from which the samples were drawn.

when do you use a paired samples t-test

Use related -samples (paired) t-test when you have one sample that you measured under two different conditions or timepoints and you want to know whether there are mean differences in the measurements. Also use for two matched samples, so you have clear pairs of scores (twin1 -twin2, father - son, husband-wife, sibling1-sibling2).

when do you use a repeated-measures anova

Use repeated-measures ANOVA when you have more than two measurements of a DV from the same set of people(under different conditions or at three different timepoints) and you want to know if there are differences among the means of the measurements in the populations

when do you use a z-test

Use z-test when you have one sample and are comparing it to a population with a known mean and known variance

A correlation coefficient r = -1 indicates 1. no correlation. 2. a perfect positive relationship. 3. a weak correlation. 4. a perfect negative relationship.

a perfect negative relationship.

A one-way repeated measures anova is also known as a) a one -way between-groups ANOVA. b) a paired-samples t test. c) a within-groups ANOVA. d) a Tukey test.

a within-groups ANOVA.

When p-value is _________, we will retain the _________ hypothesis. 1 above 0.05; alternative 2 below 0.05; null 3 above 0.05; null 4 below 0.05; alternative

above 0.05; null

How does regression differ from correlation? a) A regression analysis uses continuous variables, while a correlation analysis uses categorical variables. b) A correlation describes only one type of relationship, while a regression describes multiple relationships. c) A regression enables us to make predictions, while a correlation describes relationships. d) A correlation describes relationships, while a regression analysis tests for causation

c) A regression enables us to make predictions, while a correlation describes relationships.

Twenty-five years ago the psychology department reported 153 men as psychology majors and 104 women. You are interested in whether women are a greater proportion of majors this year than they were 25 years ago. Which statistical test would help you answer this question?

chi-square

which test: In a multiple choice test with 30 questions, 4 options per question, Lucas answered 10 questions correctly. Are we confident he knew anything at all?

chi-square goodness of fit: difference from comparison

which test: Do people in Oregon have a preference between Pepsi and Coca-cola? You sampled 50 Oregonians who drink coke and asked whether they rather get a Pepsi brand or Coca-cola brand drink.

chi-square goodness of fit: equal proportion

A developmental psychologist is interested in whether 2-year-olds have a preference among the three primary colors: red, blue, and yellow. He samples n= 70 2-year-olds, has each child pick her/his favorite color, and records the choices. Which test?

chi-square goodness of fit: equal proportions

How could you tell if grade distribution (number of As, Bs, Cs, Ds) for PSY 302 students differs between terms (Fall, Winter, Spring) of this academic year?

chi-square test for independence

Bonferroni, Holm, Tukey are all examples of 1 inference tests 2 statistical distribution 3 corrections for multiple comparisons 4 ANOVA terminology for variability

corrections for multiple comparisons

A researcher wants to test the relationship between income, measured in dollars earned per year, and social connectedness, measured in the number of friends a person has. Which statistical test you would use to answer the research question and/or analyze the data described?

correlation

How would you know if athletes' height is related to their speed?

correlation

Suppose a researcher is interested in whether there is a relationship between the amount of caffeine consumed and the number of words recalled from a list. Which test?

correlation

Wagner and Primiano investigated whether "road rage" was related to neuroticism. They had participants take a "road rage inventory" (a real test that measures irritability) and a neuroticism inventory. Which test to use?

correlation

Is there a relationship between watching violent TV shows at age 9 and aggressiveness rating by peers at age 15?

correlation (key word: relationship)

Charlotte has been dating her new partner, Anna, for one month, and she thinks the relationship is going extremely well. Being a curious scientist, Charlotte wants to know whether there is a relation between her mood and the numbers of hours she spends in a day with Anna. Charlotte has been recording her daily moods (for another project) on a 1 to 10 scale (10 indicates extremely happy) and she is also keeping a diary so she can look up how many hours each day in the last months she spent with Anna. Which test? A) Chi-square test for independence B)One-way ANOVA C)Correlation D)Linear regression

correlation: 2 continuous meausres, association

A waiter wants to know whether it is true that leaving a small chocolate with the bill will increase tips and whether the chocolate has a different influence on men than it does on women. If the waiter asked me to design an experiment to test this, what type of statistical test will I be planning on performing?

factorial ANOVA

A researcher is interested in the effects of personality and noise level on task performance. The researcher randomly selects introverts and extraverts for the personality variable. He places half of the participants in a quiet room, and the other half in a noisy room. He then measures how many errors participants make in the task. Which test?

factorial anova

A researcher is testing the effects of stress on people's moods. The experimental condition has 25 participants. The control condition has 31 participants. Which statistical test you would use to answer the research question and/or analyze the data described?

independent samples t-test

A researcher wants to compare males and females on smoking behavior. Smoking is measured as the number of cigarettes smoked each day. Which statistical test you would use to answer the research question and/or analyze the data described?

independent samples t-test

A researcher wants to know whether men and women differ in how much they enjoy watching dance performances (on a scale 1 to 7). Which test will they likely use?

independent t-test

which test: A researcher is interested in the relationship between the consumption of different types of burritos and reported hunger levels after eating. She collects a sample of 20 people who ate bean and cheese burritos and another sample of 26 who ate beef and cheese burritos and then collects reported hunger levels on a scale of 1 to 10. Which test should she use to determine if there is a difference in hunger levels between those that ate bean burritos and those that ate beef burritos?

independent t-test

A Pearson correlation coefficient measures the strength of the ________________ relationship between two variables. 1. linear 2. any 3. quadratic 4. logarithmic 5. exponential

linear

According to your textbook, an r of -.45 is considered a ___________________ correlation. 1. negligible 2. moderate 3. weak 4. strong

moderate

In a χ2 test of independence, the __________ hypothesis states that the probabilities of one variable do not depend on the probabilities of another variable.

null

Principal Jones collects data on how students in her school performed on a standardized test that is measured on an interval scale. She wants to compare her school's performance to the mean of the rest of the schools in the state. She does not know the standard deviation of scores on this test for the state. Which statistical test you would use to answer the research question and/or analyze the data described?

one sample t-test

Survey data suggest that college students spend an average of 30 hours per week studying, with a standard deviation of 4 hours. You wonder if student athletes study the same amount. You survey 25 athletes and find that they study 25 hours per week. Which statistical test you would use to answer the research question and/or analyze the data described?

one sample z-test

A car company claims that their fleet of Eco-Friendly Economy Car have an average of 37 mpg. You randomly sample and test drive 10 Eco-Friendly Economy Cars from local car dealerships and find that the average mpg is 28. Which statistical test should you use to determine if 28 is significantly different from 37?

one- sample t-test

A political analyst is interested in how urban, suburban, and rural voters differ in exposure to political campaign ads. They measure the number of minutes per week spend watching public television. What test would they employ?

one-way between subjects ANOVA

How would you determine whether dog owners, cat owners or tarantula owners have the highest IQ?

one-way, between-subjects ANOVA

A demographer hypothesized that men and women in a heterosexual relationship differentially support same-sex marriages. He randomly sampled 250 heterosexual couples and asked each wife and each husband to indicate their support for same-sex marriages on a 10-point scale. Which test should the demographer use?

paired samples t-test

One-way, repeated measures ANOVA is an extension of _________

paired t-test

The food from a local restaurant has been giving people headaches. To be sure, you have a group of friends rate their headache on a scale from zero (no headache) to 10 (you are not friends anymore) both before and after eating at this restaurant.

paired t-test

You are interested to know if the number of syllables influences memory for words. You get 12 subjects and ask them to memorize 50 words. Twenty-five of the words are one-syllable words, and 25 are three-syllable words. You find that subjects remember an average of 15 of the single-syllable words and 8 of the three-syllable words. Which statistical test you would use to answer the research question and/or analyze the data described?

paired-samples t-test

If the slope of the simple regression line is .12, then the Pearson correlation coefficient r is expected to be ____________. 1. small 2. negative 3. positive 4. large

positive

Eta squared for factor A tell us the 1 proportion of variance in the outcome variable that is explained by factor A. 2 correlation between factor A and the outcome variable 3 effect of factor A on factor B 4 covariance between factor A and the outcome variable

proportion of variance in the outcome variable that is explained by factor A.

It is advantageous to use a within- groups ANOVA compared to a between- groups ANOVA because a within-groups ANOVA: a) has a greater variance of scores. b)reduces error since the same participants contribute to each condition of the study. c) is likely to have to include more research participants in the study. d) is more likely to discover a research result that has cause-effect implications.

reduces error since the same participants contribute to each condition of the study.

How would predict the score on the final from people's number of hours slept during the term, number of classes attended, and their ten quiz scores?

regression

A political consultant gathers a focus group of 30 registered voters and records their favorability ratings for a particular candidate on a 7-point scale. The consultant gathers favorability ratings from these 30 voters again after each of several televised debates. How would the consultant determine if the candidates' favorability ratings changed across the debates?

repeated measures ANOVA

Chime wanted to know if students' sleeping habits vary over the semester. She surveyed 100 students and asked them to keep track of how many hours of sleep they got per night during the first two weeks of school, the two weeks before break, the two weeks after break, and during the last two weeks of school. Which statistical test you would use to answer the research question and/or analyze the data described?

repeated measures ANOVA

which test: You've noticed that it's getting warmer outside. To confirm this, you pick a sample of n = 10 Oregon cities. For each city, you look up the high temperature for yesterday, for one week before yesterday, and for two weeks before yesterday. Which test would you use to determine if the temperature is changing significantly from week to week?

repeated measures anova

A researcher wanted to know whether there is a relationship between reading ability and age in elementary school. He took a sample of first graders and correlated reading ability scores with age. He did not find a significant relationship. What is the most likely problem with his research design that makes his conclusions problematic? 1. generalization beyond the range 2. restricted range 3. existence of outliers 4. small sample size

restricted range

According to your textbook, an r of .75 is considered a ____________ correlation. 1. non-existent 2. weak 3. moderate 4. strong

strong

You are analyzing a data set with one categorical predictor (men or women) and one continuous outcome variable. Which statistical test should you use? 1. t-test 2. Multiple regression 3. Correlation 4. Simple regression

t-test

Given the results r(29) = -.84, p < .05, what is the most appropriate conclusion? Select all that apply 1. the results are statistically significant 2. X and Y have a positive relationship. 3. The null hypothesis is probably true. 4. X and Y have a negative relationship.

the results are statistically significant X and Y have a negative relationship.