1. A study compared the number of tree species in unlogged forest plots to similar plots logged 8 years earlier.Independent random samples of both logged and unlogged plots were analyzed and the number of tree species wasrecorded. Tables 1 and 2 present the Shapiro-Wilk normality test for both types of forest plots and the IndependentSamples t-test results. Use the information presented in these tables to answer the questions.Table 1: Tests of NormalityTests of NormalityKolmogorov-SmirnovShapiro-WilkForest PlotStatisticdfSig.StatisticdfSig.Tree_Species Logged.18112.200.93612.444Unlogged.11014.200.94514.480*. This is a lower bound of the true significance.a. Lilliefors Significance CorrectionTable 2: Independent Samples TestIndependent Samples TestLevene's Test for Equality ofVariancest-test for Equality of Means95% Confidence Interval of theDifferenceMeanStd. ErrorFSig.tdfSig. (2-tailed)DifferenceDifferenceLowerUpperEqual variancesassumedTree_Species2.751.110-2.62724.015-3.011901.14651-5.37818-.64563Equal variances notassumed-2.69723.271.013-3.011901.11661-5.32030-.70351We want to test, at the 1% level of significance, whether the mean number of species in a logged forest plot is different tothat found in an unlogged forest plot. To perform this test, we assume that the population standard deviations of loggedand unlogged forest plots are equal. e. What is the value of the observed test statistic, t, associated with the hypothesis test?0.013-2.627-2.697O 0.015

Given: Output of the test is given. Df for logged forest plot=12 Df for unlogged forest plot=14

Answered: e. What is the value of the observed…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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A health psychologist knew that corporate executives in general have an average score of 2.55 with a standard deviation of 0.5 on a stress inventory and that the scores are normally distributed. In order to learn whether corporate executives who exercise regularly have different stress scores, the psychologist measured the stress of 30 exercising executives and found them to have a mean score of 2.76. a. Using the five steps of hypothesis testing, was the group of 30 exercising executives different from executives in general? (Use the .05 significance level.) Be sure to sketch the distributions involved. Be sure to fully state the five steps and show ALL calculations/work. b. Additionally, explain the logic of what you did to a person who understands hypothesis testing for studies in which the sample consists of a single individual but is unfamiliar with hypothesis testing involving a sample of more than one individual. (Be sure your explanation includes a discussion of the…
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