Question

The amount of chromium in the diet has an effect on the way the body processes insulin. In an experiment designed to study this phenomenon, four diets were fed to male rats. There were two factors. Chromium had two levels: low (L) and normal (N). The rats were allowed to eat as much as they wanted (M) or the total amount that they could eat was restricted (R). We call the second factor Eat. One of the variables measured was the amount of an enzyme called GITH. The means for this response variable appear in the following table Eat Chromium M A plot of the mean GITH for these diets, with the factor Chromium on the x axis and GITH on the y axis is given below. For each Eat group the points for the two Chromium means are connected 54 52 0 48 4.6 EatM Low Normal Chromium level (a) Describe the patterns you see. Does the amount of chromium in the diet appear to affect the GITH mean? Does restricting the diet rather than letting the rats eat as much as they want appear to have an effect? O There is a larger difference in means based on chromium level than based on how much rats were allowed to eat. O There is a larger difference in means based on how much the rats were allowed to eat than based on chromium level. O Neither Chromium level nor the amount rats were allowed to eat made any difference in the mean GITH level. (b) Compute the marginal means. Round your answers to 3 decimal places. L Mean N Mean M Mean R Mean

Answer 1

a)

option B) is correct

There is larger difference in means on how much the rats were allowed to eat based on chromium leve

b)

		M	R
	L	4.545	5.175
	N	4.425	5.317
	L mean	4.86
	N	4.871
	M	4.485
	R	5.246