Stats

with respect to the "sampling distribution of the difference"

1. the mean, the median, the mode are equal to zero 2. the distribution of the differences must be normal

a frequency distribution would be mesokurtic if its SD was 8 and its range was:

48

with respect to experimental data, the numerator in the t ratio represents variation in the DV due to:

IV and sampling error

the average distance from the mean in a set of measurements in a sample is the definition of:

SD

with respect to experimental data, the denominator in the t ratio represents the variation in the DV due to:

all sources of variation except the IV

in the x^2 test, the null hypothesis is:

any difference between the frequency observed and the frequency expected is due to sampling error

a negative z score means that the value is:

between the 0 and 50th percentile

when we fail to reject the null, we are concluding that the results are due to:

chance, random variation, and sampling error

a political scientist wants to decide if population would vote for someone who is for or against immigration laws. She describes the two candidates, then asks which candidate they would vote for. What test would be used to measure this?

chi square

a researcher wanted to see if there was any effect on 3 different drugs. she asked if they felt better or not after taking the drug. the appropriate test will be:

chi square

with respect to the t table, an extremely large sample size/ what is true?

critical values of t become virtually identical to those in the z table

as sigma gets smaller, the standard error of the mean would:

decrease

with respect to an independent sample t test, the sample SD gets larger, the probability to rejecting the null:

decreases

the numb hypothesis for a chi square test is:

fo=fe

in an independent sample t-test, the value of t tells you:

how many standard errors of the difference the difference between sample means is from 0

as the value of inferential stats decreases, the probability that the null hypothesis:

increases

a researcher hypothesizes that a sample of men will score lower than a sample of woman on an interval scale ratio. the test used would be the:

independent sample t test

if a researcher wanted to determine annual income and whether people are democrats or republicans the appropriate test would be:

independent sample t test (because comparing 2 independent groups)

a z-test or a t-test should be used only when the DV is:

interval/ratio

what is true about standard deviation?

it can be 0

mean = 60 median = 62.5 mode = 65 what can we say about the distribution?

it is negatively skewed

what is false with respect to the sampling distribution of the difference?

it is the basis for single-sample t test

what is false with respect to sampling distribution of the mean?

its mean must always be 0

what is false with respect to a normal distribution?

its mean must always be zero

at a given t-value, the smaller the sample size:

less likely to reject the null

whether or not a mean difference between two samples is statistically significant depends on:

magnitude of the difference, the size of the sample, the amount of random variation within each sample

the sampling distribution of the ___ is a frequency distribution of an ___ taken from the same ___

mean; sample mean; population

using statistical notation, the null hypothesis for the two tailed z test would be

mew sample = mew population

____ is a parameter, while ___ is a statistic

mew;SD

a researcher asks participants to indicate if they are homosexual, heterosexual, bisexual. the variable of sexual orientation is measured on an _____ scale

nominal

a researcher thought lefties would score higher than righties given on a test. the design is ____, the Dv is ___, the IV is___

non-experimental, scores on the test, left or right handed

if class rank were the variable we are using, the level of measurement would be:

ordinal

given a data set with the standard deviation of 15 and a range of 60, you should conclude that the distribution is:

platykurtic

inferential statistics are referred to as inferential because they are used to draw conclusions about ____ from ___

populations;samples

assuming that a sample is taken at random from a population, any difference between the sample mean and the population mean is referred to as:

sampling error

the standard error of difference is:

the SD of sampling distribution of the difference

the standard error of the mean is:

the SD of the sampling distribution of the mean

the degrees of freedom for the chi square statistic is influenced by?

the number of rows and columns on the contingency table

the definition of the term "degrees of freedom" refers to?

the number of values in the data are free to vary

as sample size decreases, assuming a t-ratio remained constant, what is true regarding the null?

the probability of rejecting the null would decrease

the phrase "significant significant" means:

the result is probably not due to sampling error.

in estimating the standard error of the mean, we use the sample SD, but then divide it by the square root of n-1. why?

the sample SD is a biased estimate, consistently overestimating the population SD

compared to an alpha level of .01, if we use an alpha level of .05, we are more likely to make a:

type 1 error (accepting the null when it should have been rejected)

the mean reason why we never prove anything in social science research is that:

we draw conclusions about population from sample data

if we do not have a population SD, why can we not use the z-table to determine whether a sample men is representative of a a population?

we must estimate the SEM and the hypothetical distribution is more platykurtic except at n=infinity

a type 1 error occurs when

we reject Ho when Ho is actually true

when estimating a population mean using confidence intervals, what determines whether u use a value from a z test or a t test?

whether you have the population standard deviation (use a z test when SD population is given)

with respect to estimating a population mean, compared to a 95% confidence interval, a 99% confidence interval would be:

wider

when you know the population mean (mew) and the population standard deviation (sigma), and if you want to determine if the sample mean is significantly different from the population mean, you should use the:

z-test (comparing 2 populations with knowing the SD)