Exam 18: Choosing and Reporting Statistics

SENIC (Study on the Efficacy of Nosocomial Infection Control) has a public data set from 1975 to 1976 that contains information on 113 hospitals, including rankings according to cleanliness and the probability of acquiring an infection in the hospital.A Spearman correlation coefficient of -0.58 between cleanliness ranking (high rank = very clean) and risk of infection ranking (high rank = high risk) is found from the SENIC data set.What can be concluded from these findings?

What happens to outliers in scale data when they are converted to ordinal data?

Blake is interested in training for his first marathon and wants to determine whether the finishing place of non-elite marathon runners depends on the type of training program used.There are three training programs he is interested in comparing: Hal Higdon's, Jeff Galloway's, and Art Liberman's.Blake is able to track down 30 runners, 10 who have used Higdon's, 10 who have used Galloway's, and 10 who have used Liberman's.Blake asks the runners how they placed in the marathon.What statistic should he use to analyze his data?

The data used for a Spearman correlation are _____, whereas the data for the Pearson correlation are _____.

To use a nonparametric test despite having scale data, transform the data from scale to:

SENIC (Study on the Efficacy of Nosocomial Infection Control) has a public data set from 1975 to 1976 that contains information on 113 hospitals, including rankings according to cleanliness and the probability of acquiring an infection in the hospital.If a researcher wants to look for a relationship between these variables, what test should be used and why?

The sample size for the Wilcoxon signed-rank test is:

The Spearman correlation can be performed to examine the relation between one ordinal variable and one scale variable.

The nonparametric equivalent of the Pearson correlation coefficient is the:

The nonparametric equivalent of the independent-samples t test is the:

Nonparametric tests are usually used when the sample data are:

The nonparametric equivalent for the paired-samples t-test is the:

The nonparametric equivalent for the one-way between-groups ANOVA is the:

A researcher is transforming finishing times from a 5K race into ordinal data and has the following scores in minutes: 12.2, 16.5, 12.8, 13.4, 17.8, 13.4, 13.4, and 18.6.If the researcher ranks from fastest to slowest, what would be the rank of the three people with a finish time of 13.4?

Three different ethnic groups are compared on their ranked language skills and an H statistic of 5.1 is computed.What conclusion could be made about a hypothesis test at a p level of 0.05?

The Mann-Whitney U test is the nonparametric equivalent of the paired-samples t test.

A researcher is planning to perform a Pearson's correlation on scale data but notices several extreme outliers that appear to skew the distribution.What is the best alternative method to analyze the data?

When converting data to ranks, scores of the same value receive the lowest of the two ranks they would hold if different.

Using a p level of 0.05, a researcher performed the Wilcoxon signed-rank test with a sample size of 16 and found that the sum of the ranks for positive differences was 36 and the sum of the ranks for negative differences was 100.Which statement accurately describes the results of the hypothesis test for these data?

A political analyst categorized two groups of people as either having traveled to Europe or not traveled to Europe and asked the two groups to rank the importance of economic issues currently being debated by the European Union.The analyst wants to compare the rankings for the two groups.Which test should be used?