Answered step by step
Verified Expert Solution
Question
1 Approved Answer
Please help with 1.4 Question 1 [501 The dataset InsectSpray in the datasets package in R contains data that were collected on the counts ot
Please help with 1.4
Question 1 [501 The dataset InsectSpray in the datasets package in R contains data that were collected on the counts ot insects in agricultural experimental units treated with 6 different insecticides. The purpose of the study was to investigate the effectiveness of the sprays on the insects. use R-somvare to answer the questions that follow Present or attach the R codes and outputs used to answer the questions. 1.1 Use a boxplot to represent the data Interpret the output 12 Perform an analysis of variance and present your results on an ANOVA table. Test the hy- pothesis that there are no differences in the mean effectiveness ot the sprays using a 5% level of significance. For the test provide the null and alternative hypotheses, critical region (or rejection rejection), test statistic and conclusion. (12) 1.3 Using Tukey's honest significant difference (HSD), investigate the pairwise differences among the six sprays. Are there any significant pairwise differences at 5% level ot significance? For the tests, provide the null and alternative hypotheses, critjca/ regions (or rejection rejections), test statistics and conclusions _ (18) 1.4 For the conclusions in parts 1.2 and 1.3 to be valid, the assumptions ot normality, ho- moscedasticity and independence must be met by the data. Use the residuals trom the fitted model to examine the three conditions. (a) (b) (c) Was there a significant evidence ot a violation ot the normality condition? Explain. (5) Was there a significant evidence that the variance in the insect counts was different tor all the six sprays? Discuss. Is the assumption of independent residuals plausible? Justity your answer.
Step by Step Solution
There are 3 Steps involved in it
Step: 1
Get Instant Access to Expert-Tailored Solutions
See step-by-step solutions with expert insights and AI powered tools for academic success
Step: 2
Step: 3
Ace Your Homework with AI
Get the answers you need in no time with our AI-driven, step-by-step assistance
Get Started