PSYC 3130 Final Exam questions n
answers passed
When should you use a z-test? - correct answer ✔✔Used to test whether a sample mean is
significantly different from a population mean when we know the population mean and
standard deviation
What are the assumptions for a z-test? - correct answer ✔✔1. We have randomly selected one
sample
2. The dependent variable is at least approximately normally distributed in the population, it
involved an interval or ratio scale, and the mean is the appropriate measure of central tendency
3. We know the mean of the population of raw scores under some other condition of the
independent variable
4. We know the standard deviation of the population described by the null hypothesis; it is not
estimated using the sample
When should you use a single sample t-test? - correct answer ✔✔Used to test whether a
sample mean is significantly different from a population mean when we know the population
mean, but we do not know the population standard deviation
What are the assumptions for a single sample t-test? - correct answer ✔✔1. We have one
random sample of interval or ratio scores
2. The raw score population forms of a normal distribution for which the mean is the
appropriate measure of central tendency
3. The standard deviation of the raw score population is estimated by sx computed from our
sample
When should you use a binomial test (binomial probability distribution)? - correct answer
✔✔We use it when an experiment meets certain conditions
,What are the assumptions for a binomial test (binomial probability distriubtion)? - correct
answer ✔✔1. A single trial may result in exactly two events (called success and failure)
2. n such trials take place (n is fixed in advance)
3. The trials are completely independent
4. The probability of a success does not change over trials (stationarity)
5. We are interested in the total number of successes occurring over the n trials
When should you use an independent samples t-test? - correct answer ✔✔Used to test for
mean differences between two independent samples (ex: two different groups)
What are the assumptions for an independent samples t-test? - correct answer ✔✔1. The two
random samples of scores are measured on an interval or ratio scale
2. The population of raw scores represented by each sample forms a normal distribution, and
the mean is the appropriate measure of central tendency (if each sample n is greater than 30,
the populations need only form roughly normal distributions)
3. We do not know the variance of any raw score population and must estimate it from the
sample data
When should you use a basic 1-way ANOVA test? - correct answer ✔✔We use this as an
extension of the t-test; used when there are more than two groups
What are the assumptions for a basic 1-way ANOVA test? - correct answer ✔✔1. The
observations are drawn from a population that is normally distributed on the dependent
variable in each group
2. There is homogeneity of variance (the variability within each group is roughly the same)
3. The observations are independent (one score is unrelated to another score)
, What is a z-score? - correct answer ✔✔a) A raw score that has been converted into standard
deviation units
b) The sum of z-scores will be 0
c) Tells us how far a score is from the mean (average)
What is a random sample? - correct answer ✔✔A sample in which every member of the
population has an equal chance of being selected
What is random assignment? - correct answer ✔✔A sample can be randomly divided into two
groups; one group is assigned to the treatment condition (drug) and the other group is assigned
to the control condition (placebo); this random division of the sample into two groups is called
random assignment
What is a population? - correct answer ✔✔A larger set of data from which a sample is drawn
What is a sample? - correct answer ✔✔A small subset of a larger set of data
What are statistics? - correct answer ✔✔A number that describes a sample (ex: the sample
mean or sample standard deviation)
What are parameters? - correct answer ✔✔A number that describes a population (ex: the
population mean or population standard deviation)
What are sums of squares? - correct answer ✔✔In ANOVA, the sum of squares is used to
indicate variation
How are sums of squares partitioned in ANOVA? - correct answer ✔✔ANOVA partitions the
variation into various sources:
answers passed
When should you use a z-test? - correct answer ✔✔Used to test whether a sample mean is
significantly different from a population mean when we know the population mean and
standard deviation
What are the assumptions for a z-test? - correct answer ✔✔1. We have randomly selected one
sample
2. The dependent variable is at least approximately normally distributed in the population, it
involved an interval or ratio scale, and the mean is the appropriate measure of central tendency
3. We know the mean of the population of raw scores under some other condition of the
independent variable
4. We know the standard deviation of the population described by the null hypothesis; it is not
estimated using the sample
When should you use a single sample t-test? - correct answer ✔✔Used to test whether a
sample mean is significantly different from a population mean when we know the population
mean, but we do not know the population standard deviation
What are the assumptions for a single sample t-test? - correct answer ✔✔1. We have one
random sample of interval or ratio scores
2. The raw score population forms of a normal distribution for which the mean is the
appropriate measure of central tendency
3. The standard deviation of the raw score population is estimated by sx computed from our
sample
When should you use a binomial test (binomial probability distribution)? - correct answer
✔✔We use it when an experiment meets certain conditions
,What are the assumptions for a binomial test (binomial probability distriubtion)? - correct
answer ✔✔1. A single trial may result in exactly two events (called success and failure)
2. n such trials take place (n is fixed in advance)
3. The trials are completely independent
4. The probability of a success does not change over trials (stationarity)
5. We are interested in the total number of successes occurring over the n trials
When should you use an independent samples t-test? - correct answer ✔✔Used to test for
mean differences between two independent samples (ex: two different groups)
What are the assumptions for an independent samples t-test? - correct answer ✔✔1. The two
random samples of scores are measured on an interval or ratio scale
2. The population of raw scores represented by each sample forms a normal distribution, and
the mean is the appropriate measure of central tendency (if each sample n is greater than 30,
the populations need only form roughly normal distributions)
3. We do not know the variance of any raw score population and must estimate it from the
sample data
When should you use a basic 1-way ANOVA test? - correct answer ✔✔We use this as an
extension of the t-test; used when there are more than two groups
What are the assumptions for a basic 1-way ANOVA test? - correct answer ✔✔1. The
observations are drawn from a population that is normally distributed on the dependent
variable in each group
2. There is homogeneity of variance (the variability within each group is roughly the same)
3. The observations are independent (one score is unrelated to another score)
, What is a z-score? - correct answer ✔✔a) A raw score that has been converted into standard
deviation units
b) The sum of z-scores will be 0
c) Tells us how far a score is from the mean (average)
What is a random sample? - correct answer ✔✔A sample in which every member of the
population has an equal chance of being selected
What is random assignment? - correct answer ✔✔A sample can be randomly divided into two
groups; one group is assigned to the treatment condition (drug) and the other group is assigned
to the control condition (placebo); this random division of the sample into two groups is called
random assignment
What is a population? - correct answer ✔✔A larger set of data from which a sample is drawn
What is a sample? - correct answer ✔✔A small subset of a larger set of data
What are statistics? - correct answer ✔✔A number that describes a sample (ex: the sample
mean or sample standard deviation)
What are parameters? - correct answer ✔✔A number that describes a population (ex: the
population mean or population standard deviation)
What are sums of squares? - correct answer ✔✔In ANOVA, the sum of squares is used to
indicate variation
How are sums of squares partitioned in ANOVA? - correct answer ✔✔ANOVA partitions the
variation into various sources:
