Psy final
In a one-way ANOVA A participant score is +4 units from the value of GM. Additionally her score is -1 unit from her groups mean how far from the GM is the M
+5 units
Which of the following represents the strongest linear correlation
-.92
A persons raw score is 7 the mean is 13 and a standard deviation is 3 what is the persons Z score
-2
Suppose that b and a standardized regression for predicting college grades from high school grades is .4 and that a person had a GPA that was one standard deviation above the mean in high school. What would Z be for hat person GPA in college
.40
In a distribution of the scores the mean is always
0
For a positive linear correlation that is not perfect, the average of the cross-products of Z scores is between:
0 and 1
If x has SD2 of 23.78 and y has SD2 of 17.56, what is the standardized variance of X
1.00
A student applying to your graduate program in psychology has a GRE score of 2.5....
1.5
Assume the number of drinks one consumes the night before a quiz in the one score on that quiz are correlated at -.075 if the number of drinks that Susie consumes is two standard deviation's above the mean what will her quiz score be
1.5 standard deviation's below the mean
If a person has an IQ of 130 approximately what percentage of people have a higher IQ. Assume u=100 and o=15
2%
Play's the four steps for computing the correlation coefficient into the correct order
2,4,1,3
You are computing an independent means T test and find that S^2 (pooled) =250. If both N1 and N2 = 25 what is S^2 difference
20
If you have two samples of 15 people each, how many degrees of freedom will you have in your independent means t test
28
The regression (a) is 2 in the raw square regression coefficient (b) is 5. What is the predicted raw score (Y) for a person with a predictor variable raw-score (x) of 7
37
A consumer psychologist is interested in the effects of annual income and motivations to shop on shopping patterns of consumers. If annual income.....
6
The mean score on a creativity test is 30 and the standard deviation is 7. The distribution is normal using the percentage approximate for the normal curve how many people would attain a score between 23 and 37
68%
In a t-test for dependent means in which 10 participants are each tested twice, making a total of 10 before scores and 10 after scores what are the degrees of freedom
9
Each of the following is part of conducting a t-test for independent means except
A difference score is figured for each participant
In a factorial design a "cell" Is
A particular combination of levels of the variables that divide the groups
All of the following are examples rank order variables except
A student level of stress before an exam
If a study is conducted at the .05 significant level has 80% power then
A=5%, B=20%
In the formula Zy=B (Zx), B is equal to
All of the above
Which of the following is a formula for covariance
All of the above
The variance of a group of scores is the same as the
Average of the squared deviations from the mean
In a distribution with an even number of scores in the median will be the
Average of the two middle scores
A distribution of means in a distribution of the means of each of many samples
B and C
All of the following are reasons why Z scores are used when figuring the degree of linear correlation except
Because of the nature of the scores Z cross product will be positive in all cases
Why can a researcher not say that the results PROVE that the research hypothesis is true
Because the results of research studies are based on probabilities rather than absolutes
And a factor analysis of variance DF (within) can be calculated by
Both A and C. Subtracting the number of cells from the total N. Summing the degrees of freedom of individuals cell
The statistical notation o(m) refers to the
Both a and c
As compared to a t-test for independent means an analysis of variance
Can be used in any situation in which a t-test for independent means would be used, but a t-test for independent means cannot be used in all situations in which an analysis of variance would be used
In prediction with one predictor variable the optimal number to use for B is
Correlation coefficient
The two main branches of statistical methods are
Descriptive and inferential
The comparison distribution for a T test of independent means is a
Distribution of differences between means
The difference between scores of three and four is approximately the same as the difference between scores of 15 and 16 the type of variable known as
Equal interval
A correlation describes the relationship between two
Equal-interval numeric variables
In a class of students in which everyone is exactly 24 years old the variance would be
Exactly 0
In a histogram the vertical up-and-down dimension displays
Frequency
Do you advantage of a large sample size, like those used in polls is that they
Greatly reduce the standard deviation of the distribution of means
As the number of individuals in each sample gets larger the distribution of means
Has less variance around the mean
Beta is the probability that
If the research hypothesis is true the experiment would still fail to support it
Astudent theorizes that performance on statistics exam will be related to the number of hours spent studying. The student will be required to use _________. To test her theory
Inferential statistics
In day today life, people in formally form and test hypothesis. For example one might wonder if attending every class causes a student to get good grades, or if it's that variation between students is more important regardless of whether they attend class or not. In this example The variation between individuals
Is analogous to within-group variance
One characteristic of an F ratio is
It is never less than 0
Roughly speaking the standard deviation is the average amount that scores differ from the
Mean
For a particular known population u=100 and o^2=49 a researcher conducts a study in which 10 participants are given an example procedure to test the hypothesis that the population these 10 participants represent is different from the known population the comparison distribution mean and variance would be
Mean =100 variance =4.9
A political scientist find that the number of members of the House of Representatives that a group for Kaname is as follows .............
Median
Statistics students Susie is asked to find the most representative value for data containing income levels for the residence in earl town what value should she use
Median
A measure of central tendency for a group of scores refers to the most representative value of a group of scores. All of the following are measures of central tendency except
Metric
The _____ is usually the single best indicator of central tendency for nominal or categorical value such as religious affiliation
Mode
The most common single number in a group of scores is the
Mode
Which of the following is example of a nominal variable
Nationality of the car a person owns
I study find that the longer a book the less willing children are to read it. This relation between book length and children's interest is an example of ______ correlation
Negative
The average of the cross product of Z scores is
Never more than +1.0 or less than -1.0
If two variables, x and y, have a significant linear correlation, under what conditions can the direction of casualty be determined just from knowing the correlation coefficient
None of the above
In a 2x2 factorial ANOVA you are testing
One interaction and two main effects
The covariance of to standardize variables is equal to what
R
Compare the relative strength of these two correlation coefficient r(a) =.40 and r(b)=.80
R(b) is four times as strong as r(a)
In principle you can make a distribution of means by
Randomly taking a very large number of samples from a population, each of them the same size, and making a distribution of their means
Analyzing the data for your study requires that you complete a one-way ANOVA, which you do in SPSS the output gives you an observed significance value of .03 to seeing this you
Reject the null hypothesis
A researcher wants to know if a new type of therapy works better or worse than standard form of therapy
Research hypothesis
In a one-way ANOVA, S (x-M)^2+ S(M-GM)^2
S(x-GM)^2
If S2/1=200,S 2/2=400, S2pooled=325. What do we know about the respective sample size
Sample 2is larger than sample 1
A graph that shows the pattern of the relationship of two variables is a
Scatter diagram
On the first exam in an introductory statistics class most students did very well and only if you did poorly how would you describe the distribution of test scores
Skewed to the left
The median is greater than the mean in a distribution that is
Skewed to the left
If you were told the correlation coefficient for a study and are asked to figure the proportionate reduction in what would you do
Square r
Another name for the standard deviation of the distribution of sample means is
Standard error
Suppose that you were interested in the relation between number of years working for a particular company in a loneliness at work. You survey 40 workers at this company and figure the correlation between these two variables of -.90 this is considered a
Strong negative linear correlation
S(y-y^)^2 is the formula for
Sum of squared error
What is the main difference between a Z score and a T score
T scores are used when the population variance is unknown
To estimate population variance from a sample SS is divided from
The degrees of freedom in the sample
A " distribution of differences between means" can be thought of as a distribution of
The differences you get when you repeatedly subtract a sample mean from one population from a sample mean of another population
The magnitude of the difference between the two means in a statistical test is called
The effect size
In a perfectly symmetrical unimodal distribution
The mode is the same as the mean
In a 2x2 Analysis of variance, the degrees of freedom for each main effect are
The number of levels of the variable minus 1
The sum of squared deviations of each score from the mean of its group Plus the sum of squared deviations of each scores group mean from the grand mean equals
The sum of squared deviations of each score from the grand mean
o^2m refers to
The variance of a distribution of sample means
When a distribution is skewed to the right it means that
There are more scores piled up at the LOW end of the range
What does it mean when a researcher rejects the null hypothesis at the .05 level
There is less than 5% chance of getting such an extreme result by the chance if the null hypothesis is true
A researcher test whether there is any difference between how fast people work in the morning versus how fast they work and evening. What is the null hypothesis
There is no difference in the speed at which people work
One important advantage of using effect sizes is that
They are a standardized score making study to study comparisons easier
In which situation below what do you use a t-test for dependent means
To compare the level of reading comprehension at the beginning of speed reading class to level of reading comprehension at the end of the class
The core idea of a one-way ANOVA
To think of each score in terms of its deviation from the overall meaning of being divided into two parts
A 2x2 factorial design has
Two variables that divide the groups
Setting the significance level cutoff .10 instead of the more usual .05 increases the likelihood of
Type I error
Failing to reject the null hypothesis when the research hypothesis is true is referred to as
Type II error
For a one-way ANOVA, SS Total= SS + SS BETWEEN
WITHIN
In an F ratio, The denominator is always the____ Group estimate of the population variance
Within
There is a correlation between X and Y. If F occurred before Y, which of the following is not very likely
Y causes X
A____ describes a particular score in terms of where it fits into the overall group of scores
Z score
The test performed after the ominous test and a one-way ANOVA with three levels of independent variable to determine precisely where the different occurred is called
a post-hoc test
in a t test for independent means, because there are two samples, you end up with 2 estimates of the population variance. if the sample sizes are the same, the two estimates can be compared by
directly averaging the two estimates into one number
The standardized regression coefficient is the number you multiply by the Z score of the predictor variable to get the _____ on the criterion variable
predicted z score
in principle, you could make a distribution means
randomly taking a very large number of samples from a population.