This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: STA4502/5507 EXAM 3 Solutions Name : UFID #: 1. Featherston (1971) was interested in the relationship between the weight of tapeworms fed to dogs and the weight of the scoleces recovered from the dogs after 20 days. The cysticerci used in the experiment were collected from wheep carcasses and forcefed to 10 dogs via gelatine capsules. The scoleces were recovered from each dog at autopsy, 20 days after the introduction of the tapeworms. The mean weight of the initial cysticerci and the mean weight of the recovered worms for each of the 10 dogs are given below. Dog 1 2 3 4 5 6 7 8 9 10 Cysticerci 28.9 32.8 12.0 9.9 15.0 38.0 12.5 36.5 8.6 26.8 Worms Recovered 1.0 7.7 7.3 7.9 1.1 3.5 18.9 33.9 28.6 25.0 Do Pearsons’s correlation test (with tdistribution) , permutation test for the correlation and slope, Spearman’s rank correlation test (with normal approximation), permutation test for the Spearman rank correlation, Kendall’s tau test (with normal approximation) and permutation test for the Kendall’s tau between “Cysticerci” and “Worms Recovered”. Clarify Hypothesis and assumptions for each methods. Interprete pvalues with full sentences. (20 pts) Pearson’s correlation H : ρ = 0 H a : ρ negationslash = 0 Spearman’s rank correlation H : ρ s = 0 H a : ρ s negationslash = 0 Kendall’s tau H : τ = 0 H a : τ negationslash = 0 Pearsons’ Correlation Test with tdistribution: Pearson’s productmoment correlation data: CY and WR t = 0.0112, df = 8, pvalue = 0.9913 alternative hypothesis: true correlation is not equal to 0 95 percent confidence interval:0.6272209 0.6320196 sample estimates: cor 0.003975228 1 Spearman Rank Correlation Test with normal distribution: Spearman’s rank correlation rho data: CY and WR S = 198, pvalue = 0.5835 alternative hypothesis: true rho is not equal to 0 sample estimates: rho0.2 Kendall’s Tau Test with normal distribution: Kendall’s rank correlation tau data: CY and WR T = 19, pvalue = 0.6007 alternative hypothesis: true tau is not equal to 0 sample estimates: tau0.1555556 Number of the random permutations: R= 10000 Testing H0:rho=0 vs. Ha:rho=/=0: Pearson’s correlation of original data: 0.003975228 estimated pvalue for Pearson correlation= 0.9898 Testing H0:beta_1=0 vs. Ha:beta_1=/=0: Slope of original data: 0.00413569 estimated pvalue for Slope= 0.9898 Testing H0:rho_s=0 vs. Ha:rho_s=/=0: Spearman’s correlation of original data: 0.2 estimated pvalue for Spearman correlation= 0.5806 2 Testing H0:tau=0 vs. Ha:tau=/=0:Testing H0:tau=0 vs....
View
Full Document
 Spring '08
 Staff
 Statistics, Statistical tests, Pearson's chisquare test, Nonparametric statistics, Spearman's rank correlation coefficient

Click to edit the document details