Exam 18: Nonparametric Methods

Refer to the MegaStat/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 null hypothesis H₀: D₁ and D₂ are identical probability distributions and the alternative hypothesis of H_a: D₁ is shifted to the left of D₂.

A student is trying to decide if it is cheaper to order blank CDs over the Internet or to buy them at local electronics stores.Listed below are the prices (in dollars)quoted for boxes of 200 blank CDs from various manufacturers. \ Internet Local Electronics Stores 26.00 33.98 27.99 37.75 31.50 38.99 32.75 35.79 27.00 33.99 27.98 34.79 24.75 29.98 28.15 33.00 29.99 32.00 29.99 Set up the alternative hypothesis for the claim that buying over the Internet (I)is cheaper than buying from the local electronics stores (E).

A parametric test is always more powerful than its nonparametric counterpart.

In a manufacturing facility producing fasteners,a foreman suspects that the diameter of the bolts 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.The population of bolt diameter measurements is not normally distributed.Which one of the following nonparametric tests is appropriate for this problem?

The EPA has stipulated that the Pollution Standard Index (PSI)for clean air standards is to average no more than 100.A random sample of 9 days for the city of Acorn showed PSI readings of 144,85,90,120,150,105,93,130,and 115.Assume the population of PSI readings is highly nonnormal.The EPA wants to determine if there is significant evidence to conclude that Acorn's air is dirtier than the stipulated clean air standards.The test is conducted at α = .05 and the p value is found to be .254.Based on this result,provide a one-sentence managerial conclusion.

The Spearman's rank correlation test can be used to study the relationship between two ordinal variables.

Three years ago,a major hotel chain purchased a large number of heating and air-conditioning units from three major manufacturers,A,B,and

A study was conducted to investigate the effect of an intervention protocol on IQ tests.Nine randomly selected students were tested. Before After 100 106 111 112 93 95 92 90 99 107 85 100 117 126 110 105 98 110 At ? = .05,test to determine if the protocol increases test scores.

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:

Two NFL scouts are in the process of recruiting 7 college senior football players (receivers).After a careful review and evaluation,both scouts ranked the seven receivers in terms of their professional career prospects.The rankings are given below. Player (Receiver) Rankings of Scout 1 Rankings of Scout 2 1 3 3 2 2 1 3 1 2 4 4 6 5 5 4 6 7 7 7 6 5 At ? = .05,does it appear that the two scouts have similar opinions about the professional football career prospects of the seven players?

The __________________ test is a nonparametric counterpart of a small-sample t test for comparing two independent population locations.

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

An assumption of the Wilcoxon rank sum test is that the variances of the two populations are equal.

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

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

In a Wilcoxon rank sum test,when two or more observations are equal,we assign to each tied observation a rank equal to the _________ of the consecutive ranks.

A readability analysis is conducted to determine how easy four different newspapers are to read for the average citizen.The sample scores are below: 50 59 45 62 50 60 48 64 53 63 51 68 58 65 54 70 59 67 55 72 At the ? = .01 level of significance,test the claim that the four newspapers have the same readability level.

A local real estate agent claims that the median selling price of homes in a major midwestern city is more than $200,000.Suppose a random sample of 100 homes sold in the last six months is taken and 53 sold for over $200,000.Using ? = .01,test the real estate agent's claim.What do you conclude about the selling prices of the homes?

A student is trying to decide if it is cheaper to order blank CDs over the Internet or to buy them at local electronics stores.Listed below are the prices (in dollars)quoted for boxes of 200 blank CDs from various manufacturers. \ Internet Local Electronics Stores 26.00 33.98 27.99 37.75 31.50 38.99 32.75 35.79 27.00 33.99 27.98 34.79 24.75 29.98 28.15 33.00 29.99 32.00 29.99 What is the test statistic T?

A readability analysis is conducted to determine how easy four different newspapers are to read for the average citizen.The sample scores are below: 50 59 45 62 50 60 48 64 53 63 51 68 58 65 54 70 59 67 55 72 Calculate H.