Exam 18: Nonparametric Methods

An e-business/e-commerce information technology consulting company wants to compare the effectiveness of three programming languages that its programmers use.Currently each programming language is used by approximately 1/3 of the programmers employed by the company.The director of the programming division randomly selected 5 programmers from the users of each of the three programming languages and assigned the same simple programming task to each programmer.It is known that all three populations have highly skewed distributions with extreme outliers.Which one of the following nonparametric tests is appropriate for this problem?

A cholesterol test was given to 10 heart patients with high cholesterol levels.The same 10 heart patients are then given a new cholesterol-reducing drug for six months.Before the patients begin taking the drug,they are told to maintain their current diets and eating habits so that the effect of the drug can be more effectively determined.After taking the drug for six months,the same patients are given a cholesterol test again.The pharmaceutical company manufacturing the medicine wants to know if the drug is effective in reducing the cholesterol levels of the patients.The cholesterol levels before and after taking the drug is recorded for each patient.Distribution of cholesterol level is not normally distributed.Which one of the following nonparametric tests is appropriate for this problem?

Refer to the Mega-Stat/Excel output for the Wilcoxon rank sum test given in the table below. At a significance level of .05,which one of the following rejection point conditions is correct regarding the following null hypothesis? H₀: D₁ is shifted to the left of D₂

Two coffee-vending machines are studied to determine whether they distribute the same amounts.Samples are taken and the number of ounces is recorded for each machine. On the average,can it be concluded that the machines distribute the same amount? Test at = .05

In a manufacturing facility producing fasteners,a foreman suspects that the diameter of the bolt produced by his second shift workers is greater than the diameter of the bolts produced by his first shift workers.He takes a sample of 5 bolts from the first shift and a sample of 4 bolts from the second shift and measures the diameters in inches.Distribution of bolt diameter measurements is not normally distributed.Which one of the following nonparametric tests is appropriate for this problem?

The sign test is a test about a population median that is valid for any sample size and population shape.

The Kruskal-Wallis test is the nonparametric counterpart of the:

The Kruskal-Wallis test requires that all p samples being compared must have equal sample sizes.

Assume that the following data set is not normally distributed. (21,18,4,9,14,16,17,12,15,8,7,5) If H_a: M_d < 16,then the p-value is:

The Kruskal-Wallis H statistic can be approximated by the _____________ distritibution.

The Wilcoxon signed rank test is the nonparametric counterpart of the:

The Wilcoxon rank sum test is used to compares the locations of two _____________ populations.

The Wilcoxon rank sum test requires that two independent samples being compared must have equal sample sizes.

A professional organization is attempting to determine whether salaries of hospital CFOs differ by geographical region.Five hospital CFOs were randomly selected from each of the following four regions of the United States: East,Midwest,South,and West.Each CFO was than asked his or her annual salary.The distributions of salaries were highly skewed.The table below summarizes the results of the Kruskal-Wallis test obtained from Mega-Stat/Excel. At a significance level of .05,which one of the following statements is correct regarding the following null hypothesis? H₀: The four populations under consideration have identical locations

The signed rank test is the nonparametric counterpart of the:

Wax-com Electronics Inc.claims that a certain circuit board has a median operating life of less than 20,000 hours.A random sample of 25 such circuit boards showed 8 circuit boards failing before 20,000 hours and 17 circuit boards failing after 20,000 hours. Assume the useful life of the circuit board is not normally distributed and state the null hypothesis.

The sign test is a nonparametric test for a population mean that is valid for any sample size and population shape.

A sign test is a test of hypothesis about the population mean.

Five years ago,the average starting salary of a new college graduate with a major in marketing was $34,000.A random sample of 10 graduates from this year's graduating class of a local university yielded the following starting salaries in thousands of dollars: 28,36,25,37,35,24,38,45,39,and 36.The local university wants to determine if the median starting salary for marketing graduates has increased in the last five years. Assume that the population of starting salaries in marketing is not normally distributed.Using $\alpha$ = .05,can we conclude that the starting salaries increased in the last five years?

Refer to the Mega-Stat/Excel output for the Wilcoxon rank sum test given in the table below. At a significance level of .05,which one of the following rejection point conditions is correct regarding the following null hypothesis? H₀: D₁ is shifted to the right or left of D₂