Homework

For the problem below do:

1. State the null and alternative hypothesis.
2. Indicate the type of test to use.
3. Test for the assumptions of outliers, normality and homogeneity of variances.
4. Run the ANOVA in R.
5. Run the post-hoc test.
6. Report your results on top of a publication quality plot.
7. Describe your conclusion.

Problem: A researcher has grown plants under ambient CO2, and two CO2 treatments in which he increased CO2 by 50ppm (Treatment1) and 100ppm (Treatment2). The weight of the plants in grams were:

Control = 4.81, 4.17, 4.41, 3.59, 5.87, 3.83, 6.03, 4.89, 4.32, 4.69

Treatment1 = 4.17, 5.58, 5.18, 6.11, 4.5, 4.61, 5.17, 4.53, 5.33, 5.14

Treatment2 = 6.31, 5.12, 5.54, 5.5, 5.37, 5.29, 4.92, 6.15, 5.8, 5.26

Test for significant differences among those three groups using a significant level of 0.05.