Exam 19: Nonparametric Statistics

A nonparametric test for comparing two or more populations should be used instead of its parametric counterpart if:

Statistical tests that are not very sensitive to errors in assumptions are called parametric tests.

The Friedman test is employed to compare two or more populations when the data are generated from a randomized block experiment,and are either ordinal or interval,but not normally distributed.

You are performing the Wilcoxon rank-sum test.The 13^th through 15^th values in an ordered array of pooled sample data all equal $180 (while the 12^th value is less and the 16^th value is more).The appropriate ranks for the three $180 values are:

You can only conduct two-tail tests of the Spearman rank correlation coefficient.

Campaign Commercials It is important to sponsors of television shows that viewers remember as much as possible about the commercials.The campaign manager for a local politician is trying to decide which of two commercials to use on a weekly half-hour comedy.To help make a decision she decides to have 12 individuals watch both commercials.After each viewing,each respondent is given a quiz consisting of 10 questions.The number of correct responses is recorded and listed below.Assume that the quiz results are not normally distributed. ​ ​ -{Campaign Commercials Narrative} Does this data provide enough evidence at the 5% significance level to conclude that the responses to the two commercials differ?

If all the x values and all the y values are positive numbers,then ρ must be > 0.

The z-test approximation to the Wilcoxon rank sum test for two independent samples requires that both sample sizes are larger than 10.

Campaign Commercials It is important to sponsors of television shows that viewers remember as much as possible about the commercials.The campaign manager for a local politician is trying to decide which of two commercials to use on a weekly half-hour comedy.To help make a decision she decides to have 12 individuals watch both commercials.After each viewing,each respondent is given a quiz consisting of 10 questions.The number of correct responses is recorded and listed below.Assume that the quiz results are not normally distributed. ​ ​ -{Campaign Commercials Narrative} Which test is appropriate for this situation?

Which of the following will never be a required condition of a nonparametric test?

The nonparametric counterpart of the randomized block model of the analysis of variance is the:

The Wilcoxon rank sum test statistic T is approximately normally distributed whenever the sample sizes are larger than:

The population Spearman correlation coefficient is labeled ρ_s,and the sample statistic used to estimate its value is labeled r_s.

One of the required conditions of the sign test is that the number of nonzero differences n must be greater than or equal to 30.

Keyboard Speed Ten administration assistants were selected at random from a large university.The keyboard speed (number of words per minute)was recorded for each secretary on two different brands of computer keyboards.Assume that the typing speeds are not normally distributed.The following results were obtained. ​ ​ -{Keyboard Speed Narrative} Perform the Wilcoxon signed rank sum test at the 5% significance level.

The rejection region for the test H₀: ρ_s = 0 vs.H₁: ρ_s≠ 0 is based on the absolute value of r_s.

When the sample sizes from both populations are larger than 10,the Wilcoxon rank sum statistic has an approximate ____________________ distribution.

The nonparametric counterpart to the Pearson correlation coefficient is the ____________________ correlation coefficient.

Statistical methods that require few assumptions,if any,about the population distribution are known as parametric techniques.

A two independent sample t-test corresponds to a Wilcoxon signed rank sum test for paired samples.