Assignment6

Assignment6 - Geog306, Spring 2008 Due April 18, 2008...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Geog306, Spring 2008 Assignment 6 Due April 18, 2008 Comparison of Samples Cover page: Give the name of the test you are doing, the hypotheses, the p-value, and your conclusion to reject or not reject the null hypothesis. Attach your supporting R work. Solve these problems twice. First, calculate the following using R (or by hand), but do not use any of the “.test” commands. Then, solve the following problems using the appropriate test – t.test, wilcox.test, aov.test, oneway.test, kruskal.test, or any other of the “.test” commands that are correct for the individual problem. Use both parametric and nonparametric approaches. 1. A researcher collected data regarding the lead level in plants. He wants to know if plants near roads have more lead than plants far from roads. He collected 47 close plants and 36 far plants. The mean amount of lead in the plants close to the road was 0.07 mg; the mean amount in the plants far from the road was 0.05 mg. The sample standard deviations were 0.03 (close plants) and 0.04 (far plants). Test the researcher’s hypothesis that plants near roads have more lead than plants far from roads. Two sample difference of mean Z (independent sample) Non Parametric: Wilcoxon Rank Sum Test n1 = 47 n2 = 36 H0: mu1 = mu2 Ha: mu1 > mu2 X1bar = 0.07mg X2bar = 0.05 sd1 = 0.03 sd2 = 0.04 N = 20 z = 2.064079 pval = 0.0047 thus reject the null hypothesis 2. Twenty hedgehogs were sampled from a population in autumn (before hibernation) and weighed. The same hedgehogs were weighed again in the spring. The following data
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 5

Assignment6 - Geog306, Spring 2008 Due April 18, 2008...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online