Study Guide SSCI Exam 2
When a list of the population does not exist, the probability sampling technique most commonly used is A.simple random. B.stratified. C.systematic.D.cluster.
cluster
The ANOVA test is designed for dependent variables that have been measured at A.the interval-ratio level.B.the nominal level.C.the ordinal level.D.any level of measurement.
nominal level
Analysis of Variance based upon the effect of a single variable upon another is a A.Twoway ANOVA.B.Oneway ANOVA. C.Multiple ANOVA. D.None of these choices are correct.
.B.Oneway ANOVA
The critical region is A.the area under the curve that contains "non-rare" events.B.the area under the curve that includes those values of a sample statistic that will lead to rejection of the null. C.a confidence interval. D.a law that states that the shape of the sampling distribution is normal.
.B.the area under the curve that includes those values of a sample statistic that will lead to rejection of the null
A sample selected according to the principle of EPSEM is extremely likely to be A.large. B.biased.C.representative. D.inaccurate.
C.representative.
Under what conditions would you use the t distribution to test the significance of a single sample proportion? A.None, use the Z distribution as long as sample size is large. B.Only when the population standard deviation is known. C.Only when sample size is less than or equal to 120. D.Only when the population is normally distributed.
A.None, use the Z distribution as long as sample size is large.
Which assumption must be true in order to justify the use of hypothesis testing? A.Random sampling B.Interval-ratio level of measurement C.Very large samples D.Samples have been stratified
A.Random sampling
Samples of Republicans and Democrats have been tested for their level of support for welfare reform and the null hypothesis has been rejected. What may we conclude? A.The difference is significant, there are differences between the parties on this issue B.The difference is significant, the parties are the same on this issue C.The difference is not significant D.A Type I error has occurred
A.The difference is significant, there are differences between the parties on this issue
In the ANOVA test, what assumption must be made about the shape of the population distribution? A.The population distribution is normal in shape B.The test is non-parametric, no assumption need be made about the population C.Population distribution is a bivariate table D.The test is parametric, population distribution is assumed to not be normal
A.The population distribution is normal in shape
Nonprobability samples are useful for: A.generalizing findings to a population.B.pretesting a larger project. C.finding causal relationships. D.nonprobability samples are never useful
B.pretesting a larger project.
The F ratio is a ratio of _____ to ____ . A.amount of variation between categories, the amount of variation within B.amount of variation within categories, the amount of variation between C.total variation, amount of variation between D.total variation, amount of variation within
A.amount of variation between categories, the amount of variation within
Compared to probability samples, non-probability samples A.are usually cheaper to assemble. B.are always much larger. C.are usually more expensive to assemble. D.allow for generalizations to populations.
A.are usually cheaper to assemble.
In a sampling distribution of sample means, most of the sample means will A.cluster around the true population value. B.be below the population mean in value. C.be above the population mean in value. D.not follow any particular pattern
A.cluster around the true population value.
The research hypothesis (H1) typically states what the researcher expects to find and A.contradicts the null hypothesis. B.verifies on the null hypothesis. C.modifies the null hypothesis. D.is unrelated to the null hypothesis.
A.contradicts the null hypothesis.
If the critical region begins at Z (critical) = ± 2.56 and the test statistic is - 2.50, we A.fail to reject the null hypothesis. B.reject the null hypothesis. C.cannot make a decision because the test statistic is so close to the critical region. D.change the alpha level.
A.fail to reject the null hypothesis.
Republicans average 1.4 children while the state as a whole averages 1.7 children. The Z score computed in this test is 0.78 and the alpha level is 0.05. Therefore, the difference in size of family A.is due to random chance. B.does not reflect the situation of all Republicans. C.is significant. D.All of the above
A.is due to random chance.
Like estimation procedures, hypothesis testing involves the risk that the sample A.may not be representative. B.may not be biased. C.may be too large. D.may not be significant.
A.may not be representative.
Two sample statistics are unbiased estimators. They are A.means and proportions. B.means and standard deviations. C.medians and prmodes. D.proportions and percentages.
A.means and proportions.
If our F (obtained) exceeds the F (critical), we A.reject the null. B.accept the null. C.must recompute since this is mathematically impossible. D.
A.reject the null.
What are the three distributions involved in every application of inferential statistics? A.sample, sampling, and population B.sample, stratification, cluster C.EPSEM, random, probability D.sampling, percentage, normal
A.sample, sampling, and population
The General Social Survey (GSS) is an example of a A.sample. B.sampling distribution. C.population. D.All of the above
A.sample.
The research hypothesis for the ANOVA test is a. μ1 < μ2 < μ3 < ... < μN. A.that at least one population mean is different. B.SST = SSB = SSW. C.that at least one of the sums of squares is different.
A.that at least one population mean is different.
The lower the alpha level, A.the lower the probability of rejecting the null hypothesis. B.the larger the sample size has to be to reject the null hypothesis. C.the greater the probability of rejecting the null hypothesis. D.the more desirable the two-tailed test.
A.the lower the probability of rejecting the null hypothesis.
If we reject a null hypothesis of "no difference" at the 0.05 level A.the odds are 20 to 1 in our favor that we have made a correct decision. B.the null hypothesis is true. C.the odds are 5 to 1 in our favor that we have made a correct decision. D.the research hypothesis is true.
A.the odds are 20 to 1 in our favor that we have made a correct decision.
Why would researchers use the t distribution? A.the population standard error is usually unknown. B.it is best for larger samples. C.it always has more accurate results. D.the Z distribution is always preferable.
A.the population standard error is usually unknown.
If we fail to reject the null hypothesis in a test using analysis of variance, we are concluding that A.the populations from which our samples come are the same. B.the samples are dependent. C.the population variances are the different. D.the sample means are different.
A.the populations from which our samples come are the same.
A one-tailed test of significance could be used whenever A.the researcher can predict a direction for the difference. B.the researcher feels like it. C.the null hypothesis is thought to be true. D.the alpha level exceeds 0.10.
A.the researcher can predict a direction for the difference.
In estimation procedures, the alpha level is A.the same as the confidence level. B.the parameter we are trying to estimate. C.always greater than the standard error. D.equal to the efficiency ratio minus the bias coefficient.
A.the same as the confidence level.
When using sample means as estimators, we usually estimate the population standard deviation with A.the sample standard deviation. B.the sampling distribution standard deviation. C.the population parameter. D.the Z score.
A.the sample standard deviation
The Central Limit Theorem states that as sample size becomes large A.the sampling distribution of sample means approaches normality. B.the sampling distribution of sample means becomes larger. C.the population distribution becomes normal. D.the sample distribution becomes normal.
A.the sampling distribution of sample means approaches normality.
We can estimate the probability that sample means and proportions lie within a given distance of the population value because these statistics are A.unbiased. B.efficient. C.random. D.biased.
A.unbiased.
The sample standard deviation is a biased estimator of the population standard deviation. When using sample means as estimators, we correct for bias in the formula for finding confidence intervals by A.using N - 1 rather than N. B.using N rather than N - 1. C.using s rather than Z. D.squaring the value of Z.
A.using N - 1 rather than N
In the ANOVA test, degrees of freedom within (dfw) are equal to (N - k) and degrees of freedom between (dfb) A.(N - k)B.(k - 1) C.(N + k) D.(k - N)
B.(k - 1)
In the formulas for constructing interval estimates based on sample proportions, the expression Pu (l - Pu) has a maximum value of A.0.50B.0.25 C.1.00 D.0.75
B.0.25
The most commonly used confidence level is A.99.5%B.95% C.90.5% D.90%
B.95%
A researcher conducted a survey to determine if older people have different feelings about abortion than younger people. He used an alpha level of 0.05 (Z critical = ±1.96) to test for significance and found that his computed test statistic was 2.76. Which of the following conclusions is justified? A.Feelings about abortion do not vary by age.B.Older and younger people have significantly different feelings about abortion. C.A one-tailed test should have been used. D.A Type II error has occurred.
B.Older and younger people have significantly different feelings about abortion.
Which of the following is NOT an assumption required for a test of hypothesis with a single sample mean? A.A representative sampleB.Sample size (N) larger than 1,000 C.Normal sampling distribution D.Interval-ratio level of measurement
B.Sample size (N) larger than 1,000
All other things being equal, larger sample will cost more to process A.but will not necessarily have narrower confidence intervals.B.and will always produce narrower confidence intervals. C.and will always produce wider confidence intervals. D.but will produce more precise intervals if the confidence level is low.
B.and will always produce narrower confidence intervals.
As sample size increases, confidence interval width A.increases.B.decreases. C.remains the same. D.changes proportionally.
B.decreases.
The population variance is a measure of A.central tendency.B.dispersion. C.location. D.degrees of freedom.
B.dispersion.
The larger the sample size (N), the A.smaller the parameter.B.greater the efficiency. C.lower the bias. D.larger the standard error of the mean.
B.greater the efficiency.
With the ANOVA test, the ______ the difference between categories, relative to the differences within, the _____ likely that the null hypothesis will be rejected A.smaller, moreB.greater, more C.smaller, less D.b & c are both correct
B.greater, more
If we reject a null hypothesis which is in fact true, we A.have made a correct decision.B.have made a Type I error. C.have made a Type II error. D.should have used a one-tailed test.
B.have made a Type I error.
In estimation procedures, as the alpha level decreases, the corresponding Z score A.moves closer to the mean of the sampling distribution.B.moves away from the mean of the sampling distribution. C.becomes negative. D.becomes positive.
B.moves away from the mean of the sampling distribution.
The theorems presented in Chapter 6 tell us that if a sample is "large" the sampling distribution will be A.the same shape as the population.B.normal. C.small. D.irrelevant.
B.normal.
In hypothesis testing, the______ is the critical assumption, the assumption which is actually tested. A.research hypothesisB.null hypothesis C.assumption of a normal sampling distribution D.assumption that the sample was randomly selected
B.null hypothesis
In a test using ANOVA, the average ages of three different samples are 37.56, 37.57, 37.58. This pattern would be consistent with the assumption that the A.null hypothesis is false.B.null hypothesis is true. C.research hypothesis is false. D.sample standard deviations approach zero.
B.null hypothesis is true.
When testing for the significance of the difference between two samples, the null hypothesis states that the A.sample meansB.population means C.sampling distributions D.population standard deviations
B.population means
In an ANOVA test, when the null hypothesis is rejected, we know that at least one of the means is significantly different from the others. In order to find out which mean(s) are significantly different, we must conduct a A.t test.B.post hoc test. C.post mortem test. D.chi square test.
B.post hoc test.
Unless a sample is , it cannot be used to make accurate generalizations to a population. A.very large B.very smallC.representative D.stratified
C.representative
If the test statistic falls in the critical region, we A.reject the null and conclude that the research hypothesis is true.B.reject the null and conclude that there is strong - although indirect - support for the research hypothesis. C.accept the null. D.fail to reject the null.
B.reject the null and conclude that there is strong - although indirect - support for the research hypothesis.
The ANOVA test will tolerate some violation of the model assumptions as long as A.sample size is quite small.B.sample sizes are roughly equal. C.at least one sample is greater than 50. D.there are more than 4 separate samples.
B.sample sizes are roughly equal.
A sampling technique that allows you to ensure proportional representativeness in a sample is A.representative sampling.B.stratified sampling. C.systematic sampling. D.simple sampling.
B.stratified sampling.
When conducting hypothesis tests for two sample means, the test statistic is A.alpha.B.the difference in sample means. C.the degrees of freedom. D.the difference in the population means.
B.the difference in sample means.
When solving the formula for finding Z(obtained) with sample proportions in the two-sample case, we must first estimate A.the standard deviation of the population.B.the population proportion. C.the ratio of the sample proportions. D.the critical region.
B.the population proportion.
In the ANOVA test, if the null hypothesis is true A.the sample standard deviations should be zero.B.the sample means should be roughly equal in value. C.the population means should be very different from each other. D.alpha should be less than zero.
B.the sample means should be roughly equal in value.
A researcher is interested in the effect that neighborhood crime-watch efforts have on the crime rate in the inner city, but he is unwilling to predict the direction of the difference. The appropriate test of hypothesis would be A.one-tailed.B.two-tailed. C.descriptive. D.symmetrical.
B.two-tailed.
The quantity SSW measures the amount of variation A.after subtracting the total variation (SST).B.within the categories. C.in the population. D.assuming the null hypothesis is true.
B.within the categories.
The shape of the sampling distribution of sample means can be assumed to be normal when N is A.a large percentage of the population. B.any number as long as you know the value of the population mean.C.100 or more. D.at least twice the value of the population standard deviation.
C.100 or more
A null hypothesis that states "the population means are equal" would be appropriate for which of the following tests A.Chi square B.Tests of proportionsC.ANOVA D.Fisher's Exact test
C.ANOVA
The text reports a famous incident in which was incorrectly predicted to defeat . A.Kennedy, Nixon B.Nixon, KennedyC.Dewey, Truman D.Reagan, Bush
C.Dewey, Truman
A researcher has analyzed differences in average College Board scores for random samples of students from four different colleges. The obtained F score is 0.45. What can be concluded about the null hypothesis? A.Nothing, more information is needed B.Reject, the differences did not occur by random chanceC.Fail to reject, differences are not statistically significant D.Fail to reject, differences are statistically significant
C.Fail to reject, differences are not statistically significant
Sixty percent of the respondents in a random sample drawn from a neighborhood are Democrats. The community as a whole is 75% Democrat. The difference between sample and population has been tested and the null hypothesis has been rejected. What may we conclude? A.Type I error has been committed. B.A one-tailed test has been used.C.The neighborhood is significantly less likely to be Democrat. D.The difference is not significant.
C.The neighborhood is significantly less likely to be Democrat.
A pooled estimate A.compares two different populations. B.combines two different populations.C.combines information from two samples. D.is the mean of two standard deviations.
C.combines information from two samples.
The total sum of squares (SST) is found by subtracting the overall mean from _____ and squaring and summing the differences. A.the category means B.the category totalsC.each of the scores D.the sum of squares between
C.each of the scores
A researcher tests a theory about sexism by administering a survey to the 200 students in her sociology classes. This sample is best characterized as a A.cluster sample. B.stratified random sample.C.non-probability sample. D.sampling distribution.
C.non-probability sample.
ANOVA proceeds by developing two separate estimates of the A.population mean. B.population standard deviation.C.population variance. D.sample variance.
C.population variance.
ANOVA may be thought of as an extension of the _____ . A.confidence interval estimation procedure B.t test for the significance of the difference between two sample proportionsC.t test for the significance of the difference between two sample means D.t test for the significance of the difference between two matched samples
C.t test for the significance of the difference between two sample means
The sampling distribution for the ANOVA test is A.the Z distribution. B.the t distribution.C.the F distribution. D.None of the above
C.the F distribution.
A random sample of 500 reports an average yearly income of $42,000 with a standard deviation of $1000. An estimate of the parameter at the 95% level is about $175 wide. In this research situation A.the parameter is $42,000. B.the sample is unrepresentative.C.the alpha level is 0.05. D.the sample mean is $175.
C.the alpha level is 0.05
The probability of Type I error is A..01 B..05C.the alpha level. D.beta.
C.the alpha level.
The higher the alpha level, A.the lower the probability of rejecting the null hypothesis. B.the larger the sample size has to be to reject the null hypothesis.C.the greater the probability of rejecting the null hypothesis. D.the more desirable the two-tailed test.
C.the greater the probability of rejecting the null hypothesis
An estimator is unbiased if the mean of its sampling distribution is equal to A.the midpoint of the distribution. B.the sample mean.C.the population value. D.the population median.
C.the population value.
When testing for the significance of the difference between two sample means, the null hypothesis is that A.the sample standard deviations are different. B.the sample means are different.C.the populations from which the sample was drawn are different. D.the populations from which the sample was drawn are the same.
C.the populations from which the sample was drawn are different.
From a random sample of 300 students at a state university, you find the average number of hours of study time each week is 30 with a standard deviation of 5. In this research situation, A.the sample is too small. B.the population consists of the 300 students surveyed.C.the sample is the 300 students surveyed. D.the parameter is 30.
C.the sample is the 300 students surveyed.
For tests of significance involving two sample proportions, the value of the population proportion is estimated from A.the value of the sample means. B.the value of Z (obtained).C.the sample proportions. D.the sample standard deviations.
C.the sample proportions.
The width of an interval estimate can be controlled by A.changing the confidence level. B.changing the alpha level. C.changing the sample size.D.Any of the above
D.Any of the above
A random sample of 200 includes 100 Protestants. The researcher estimates, at the 95% confidence level that between 43% and 57% of the population is Protestant. In this research situation A.the parameter is 200 B.Pu is .43 or .57 C.N is 100D.alpha is 0.05
D.alpha is 0.05
The ANOVA test is most appropriate for dependent variables that are A.discrete and ordinal. B.discrete and continuous. C.continuous and nominal.D.continuous and interval-ratio.
D.continuous and interval-ratio.
The t distribution, compared to the Z distribution, is A.more skewed. B.more peaked for small samples but increasingly like the Z distribution as N increases. C.bimodal.D.flatter for small sample sizes but increasingly like the Z distribution as N increases.
D.flatter for small sample sizes but increasingly like the Z distribution as N increases.
For a simple random sample, each case and each combination of cases in the population must A.be representative.B.be included in the sample.C.be contacted by the researcher.D.have an equal probability of being chosen for the sample.
D.have an equal probability of being chosen for the sample.
The central problem in the case of two-sample hypothesis test is to determine A.if the samples are random. B.if sample statistics are the same as those of the sampling distribution. C.if the parameters are representative of the populations.D.if two populations differ significantly on the trait in question.
D.if two populations differ significantly on the trait in question.
In order to conduct a test of hypothesis with means or proportions, the sampling distribution must be A.skewed. B.large. C.bimodal.D.normal.
D.normal.
Statistics are characteristics of samples while______are characteristics of . A.percentages, populations B.medians, clusters C.parameters, stratified samplesD.parameters, populations
D.parameters, populations
When testing for the significance of the difference between two sample means, the standard deviation of the sampling distribution is estimated using A.population standard deviations. B.the standard error of the means. C.degrees of freedom.D.sample standard deviations corrected for bias.
D.sample standard deviations corrected for bias.
When conducting hypothesis tests for two sample means, the term μ1 - μ2 in the numerator of the formula reduces to zero because A.the st andard deviations are calculated first. B.the tests are conducted at very low alpha levels. C.the samples are independent as well as random.D.the null hypothesis is assumed to be true.
D.the null hypothesis is assumed to be true.
In a two person race, if the Republican presidential candidate is projected to attract 44% ± 3% of the vote and the Democratic candidate is projected to attract 46%±3% of the vote, then A.the Republican is the probable winner. B.the Democrat is the probable winner. C.neither candidate will win a majority of votes in the electoral college.D.the race is "too close to call."
D.the race is "too close to call."
As noted in the text, telemarketers often use A.simple random sampling only. B.stratified sampling only. C.non-probability sampling only.D.the sampling techniques used by social scientists.
D.the sampling techniques used by social scientists.
Which of the following combinations would result in a Type I error? The null hypothesis is actually and our decision in Step 5 is to the null hypothesis. A.false, fail to reject B.false, reject C.true, fail to rejectD.true, reject
D.true, reject
Based on an EPSEM sample of 300 state university students, we estimate that the average number of hours of study A.300. B.30. C.± 2.D.unknown.
D.unknown.
According to the example in your text, what is the difference in perspectives regarding premarital sex? A.there were no significant differences. B.men were significantly less supportive of it. C.women were significantly more supportive of it.D.women were significantly less supportive of it.
D.women were significantly less supportive of it.
With alpha set at .05, the Critical Region for a two-tailed test would begin at ± 1.96. In a one-tailed test at the same alpha level the Critical Region would begin at A.± 1.96. B.± 2.58. C.± 2.30.D.± 1.65.
D.± 1.65.
When random samples are drawn so that the selection of a case for one sample has no effect on the selection of cases for another sample, the samples are A.dependent.B.independent. C.simple. D.systematic.
independent
For testing the difference between two sample means, the level of measurement is assumed to be A.nominal. B.ordinal.C.interval-ratio. D.Any of the above
interval-ratio
The sizes of four samples vary as follows: Sample A, N = 100 Sample B, N = 76 Sample C, N =1000 Sample D, N = 150 Which sample will produce the most efficient estimate? A. Sample A B.Sample B C.Sample C D.Sample D
sample c
In tests of significance, if the test statistic falls in the critical region, we may conclude that A.the population distribution is normal.B.the null hypothesis can be rejected. C.the research hypothesis is true. D.our sample size was too small.
the null hypothesis can be rejected.
When testing hypotheses using two small samples, the t distribution may be used only after the additional assumption that: A.the population means are equal.B.the population variances are equal. C.the population variances are not equal. D.the population means are different.
the population variances are equal.
When testing for the significance of the difference between two sample means, we must first estimate A.the standard deviation of the sampling distribution B.the standard deviations of the samples C.the population means D.the critical region
the standard deviation of the sampling distribution
When testing for the significance of the difference between sample means with small samples, the proper sampling distribution is A.the alpha distribution. B.the beta distribution. C.the Z distribution.D.the t distribution.
the t distribution
If a researcher changes from the 90% confidence level to the 95% level, the confidence interval will A.widen. B.decrease in width. C.not be affected. D.widen only if N is greater than 100.
widen