Q&A Hero

Q: List the practical steps for interpreting t-test results.

Q: Explain what an independent samples t-test is and the null hypothesis examine.

Q: A researcher has data on viewers' responses regarding what company sponsored the Super Bowl half-time show for the past two years and has coded it "1" if the response was correct and "0" if not. He would like to examine if there is a statistical difference in correct answers between the two years. Explain what statistical test is appropriate to address this research question.

Q: Discuss the factors that influence the statistical choice. If a researcher is examining factors that influence an automobile's gas mileage, which statistical tool (or tools) is appropriate?

Q: The F-test partitions total variance into ______ variance and ______ variance.

Q: The statistical test for an ANOVA model is the ______.

Q: The sum of differences between the group mean and the grand mean summed over all groups for a given set of observations is called _____ variance.

Q: The _____ is the mean of a variable over all observations.

Q: _____ is the appropriate statistical tool to use when comparing the means of three or more groups to see if they are significantly different from one another.

Q: The _____ for differences of proportions is a technique used to test the hypothesis that proportions are significantly different for two independent samples or groups.

Q: An appropriate test for comparing the scores of two interval variables drawn from related populations is the _____.

Q: One way to interpret the meaning of the results of the t-test is to focus on the ________ and the group means.

Q: In using the t-test to compare the difference between the means of two groups, the formula for determining the degrees of freedom is ______.

Q: The _____ is an estimate of the standard error for a t-test of independent means that assumes the variances of both groups are equal.

Q: When a researcher needs to compare means for a variable grouped into two categories based on some less-than interval variable, a(n) _____ test is appropriate.

Q: Proper use of the c2 test requires that each expected frequency have a value of at least _____.

Q: The formula for determining the degrees of freedom for a chi-square test is ______.

Q: The ______ test studies the significance of a contingency table.

Q: A test of a hypothesis to determine if two groups differ with respect to the scores on one variable is called a(n) ______.

Q: Practically speaking, what is the first thing a researcher should do when interpreting ANOVA results? A.examine the actual means for each group B.determine the between-groups variance C.examine the total variance D.check whether or not the overall model F is significant

Q: The F-distribution is a function of _____. A.SSB - SSE B.SSE - SSB C.SSB/SSE D.SSE/SSB

Q: All of the following are forms of variance considered in an F-test EXCEPT _____. A.SSE B.SSB C.SSR D.SST

Q: The key statistical test for an ANOVA model is the _____. A.c2 test B.t-test C.F-test D.Z-test

Q: The sum of the differences between observed values and the group mean for a given set of observations is known as the _____. A.within-group error B.between-groups variance C.F-ratio D.g statistic

Q: Which of the following is the sum of differences between the group mean and the grand mean summed over all groups for a given set of observations? A.between-groups variance B.total error variance C.F-statistic D.c2 value

Q: The mean of a variable over all observations is called the _____. A.master mean B.average mean C.grand mean D.ANOVA mean

Q: Which should be used when comparing the means of three groups to see if they are significantly different from one another? A.One-group t-test B.ANOVA C.Three-group t-test D.Chi-square test

Q: In an ANOVA test of the differences between the means of three groups, the null hypothesis is _____. A.m1 = m2 = m3 B.m1 m2 m3 C.m1 - m2 - m3 = 0 D.m1 + m2 + m3 = 1

Q: _____ involves the investigation of the effects of one treatment variable on an interval-scaled dependent variable and determines whether statistically significant differences in means occur between two or more groups. A.Analysis of variance (ANOVA) B.Regression analysis C.Cross-tabulation D.c2

Q: In using the Z-test for comparing two proportions, if the pooled estimate of the proportion of successes is 0.36, then the pooled estimate of proportion of failures is _____. A.1 B.0.36 C.0.64 D.0.13

Q: The Z-test for comparing two proportions is appropriate with which null hypothesis (H0)? A.p1 = p2. B.p1 p2. C.p1 x p2 = 1 D.p1 - p2 = 1

Q: Describe the chi-square test for goodness-of-fit and explain when it is the appropriate test.

Q: Define one- and two-tailed univariate tests and describe when each is appropriate. Give an example hypothesis that can be tested with each test.

Q: Compare and contrast parametric statistics and nonparametric statistics.

Q: You are designing a research study and are determining the appropriate statistical technique to use. List the factors you should consider when choosing the appropriate statistical technique.

Q: Compare and contrast Type I errors and Type II errors and explain which one is of more concern to researchers.

Q: Compare and contrast significance levels and p-values.

Q: Explain the appropriate statistical analysis for the following hypothesis: H1: The average income of accountants is greater than $50,000.

Q: A general term representing how well some computed table or matrix of values matches some population or predetermined table or matrix of the same size is _____.

Q: The appropriate test for testing hypotheses about frequencies arranged in a frequency or contingency table is the _____ test.

Q: In hypothesis testing, the number of observations minus the number of constraints needed to calculate a statistical term is called the ______.

Q: The symmetrical, bell-shaped distribution that has a mean of zero and a standard deviation of one is called the ______.

Q: The appropriate test to use when testing hypotheses involving an observed mean against some specified value is the univariate ______ .

Q: When the researcher does not know how the data are distributed, the researcher should use ________ methods of statistics in analyzing the data.

Q: When the data are interval or ratio scaled and the sample size is large, _____ statistical procedures are appropriate.

Q: The error caused by failing to reject the null hypothesis when, in fact, the alternative hypothesis is true is called a(n) ______ error.

Q: The error caused by rejecting the null hypothesis when, in fact, it is true is called a(n) ______ error.

Q: In hypothesis testing, the values that lie exactly on the boundary of the region of rejection are referred to as the ______ values.

Q: Another name for an observed or computed significance level is _____.

Q: The critical probability associated with a statistical hypothesis test that indicates how likely it is that an inference supporting a difference between an observed value and some statistical expectation is true is called _____.

Q: A statement which expresses the opposite of the null hypothesis is called the ______ hypothesis.

Q: Analyses that test hypotheses and models involving multiple (three or more) variables or sets of variables are referred to as _____ statistical analyses.

Q: The type of statistical analysis that deals with a hypothesis about a single variable (e.g. market share) is called ______ statistical analysis.

Q: Which of the following tests is conceptually similar to the one used when the mean is the characteristic of interest but that differs in the mathematical formulation of the standard error of the proportion? A.hypothesis test of a proportion B.c2 test C.goodness of fit test D.degrees of freedom test

Q: Suppose that past research studies have found that 70 percent of a particular target market segment were aware of the Nike "swoosh" brand mark. If 65 percent of this target market in a sample of 60 people are aware of this brand mark, and if the standard error of the proportion is 0.06, the observed Z-test value is approximately _____. A.-13.19 B.-0.83 C.0.83 D.13.19

Q: In a brand awareness study of 80 consumers, 52 of them were able to identify "Fusion" as a type of Ford automobile. The chi-square value for a test of this brand awareness was approximately _____. A.2.30 B.7.20 C.0.60 D.3.60

Q: For which statistical test does the formula given below apply? A.Z-test B.F-test C.Chi-square test D.W-square

Q: Which of the following represents how well some computed table or matrix of values matches some population or predetermined table or matrix of the same size? A.statistical power B.Z-value C.t-value D.goodness-of-fit (GOF)

Q: Laura has a frequency table with the number of stores in three different categories: stand-alone, shopping center, and mall locations. Which statistical test is appropriate for testing hypothesizes she might have regarding these frequencies? A.b test B.c2 test C.a test D.g test

Q: Which type of t-test is appropriate to test the following hypothesis? H: The number of employees who commute to work is greater than ten. A.Type I B.Type II C.one-tailed D.two-tailed

Q: Suppose that a group of 100 consumers are asked to rate how much they liked the taste of a new soft drink on a 5-point scale (where 5 = good taste and 1 = poor taste) and the mean rating was 4.2 with a standard deviation of 1.48. Suppose, further, that the standard error of the mean for this study was 0.15. If you wanted to find the 95 percent confidence interval (two-tailed test), and if the Z-value at the 0.05 level of significance is 1.96, the confidence interval lies between _____. A.3.91 and 4.49 B.4.17 and 4.23 C.3.98 and 4.42 D.4.00 and 5.00

Q: For a one-group t-test, the degrees of freedom are _____. A.n + 1 B.n(n - 1) C.n - 1 D.n(n + 1)

Q: The number of observations minus the number of constraints or assumptions needed to calculate a statistical term is called the _____. A.statistical power B.t-level C.degrees of freedom D.significance level

Q: When sample size (n) is larger than _____, the t-distribution and Z-distribution are almost identical. A.10 B.20 C.25 D.30

Q: The t-distribution has a mean of ______ and a standard deviation of ______. A.one; zero B.zero; one C.one; two D.two; one

Q: When a researcher wishes to analyze data that is nominal, which type of statistics is appropriate? A.Type I B.Type II C.parametric D.nonparametric

Q: When the data are in ______ form, and the sample size is ______ , the researcher should use parametric statistical procedures. A.nominal; large B.ordinal; large C.interval; large D.nominal; small

Q: Which type of statistics involves numbers with known, continuous distributions? A.Type I B.Type II C.parametric D.nonparametric

Q: Selection of the appropriate statistical test to use in a research study depends on all of the following EXCEPT _____. A.the type of research question asked B.the number of variables C.the measurement scale used D.the statistical software used

Q: When the probability of a Type II error is ______ , the probability of a Type I error is _____. A.reduced, increased B.reduced; reduced C.increased; increased D.none of these choices

Q: Failing to identify a hypothesized difference using a sample result when one really does exist in the population is which type of error? A.primary B.secondary C.Type I D.Type II

Q: When a researcher sets an acceptable significance level a priori (a), he or she is determining how much tolerance he or she has for which type of error? A.Type I B.Type II C.Type A D.Type B

Q: Which type of error occurs when the researcher concludes a relationship exists when in fact one does not exist? A.Type I B.Type II C.Type A D.Type B

Q: The error caused by rejecting the null hypothesis when it is, in fact, true is called a _____. A.Type II error B.confidence level error C.confidence interval error D.Type I error

Q: The two types of errors researcher run the risk of committing when sampling are _____. A.primary and secondary errors B.Type I and Type II errors C.critical and noncritical errors D.Type A and Type B errors

Q: If the population mean is expected to be 85 and the sample mean is 80, the sample standard deviation is 20, and the sample consists of 100 consumers, the observed value of the Z-statistic is approximately _____. A.2.50 B.-10.00 C.-2.50 D.-0.25

Q: The values that lie exactly on the boundary of the region of rejection for hypothesis-testing are called the _____. A.degrees of freedom B.critical values C.significance level D.confidence interval

Q: In statistical testing, the significance level is commonly denoted by the symbol _____. A.b B.a C.Zobs D.c

Q: A researcher is testing a hypothesis and is examining the data to determine whether or not the observed relationship between a salesperson's age and sales are significantly related. Which of the following will he use to determine the significance level of the results? A.c B.e C.y-value D.p-value

Q: Which of the following represents the acceptable Type I error? A.t-value B.c2 C.degrees of freedom D.significance level