Question

A researcher wishes to determine the effect of chemicals (A, B) on root growth in pea plants. Seedlings of pea plants are grown for 30 days in the presence of chemicals A and B in separate groups with group C serving as the control. The researcher would like to know if there is a mean difference between the groups and if so, which chemical produced the greatest results. What would be the first step in the analysis?

A. Test normality of the residuals
B.		Test the homogeneity of variances
C.		Run a two way ANOVA
D.		Test the normality of the data

Answer 1

Here given that a researcher wishes to determine the effect of chemicals (A, B) on root growth in pea plants. Seedlings of pea plants are grown for 30 days in the presence of chemicals A and B in separate groups with group C serving as the control.  The researcher would like to know if there is a mean difference between the groups and if so, which chemical produced the greatest results.

So first we will test the normality of the data. Option D is correct here.