Question

How does smoking affect testosterone levels in males?

Here is some data, where testosterone was measured in 10 men randomly selected from each of 4 populations:

	nonsmoker	former smoker	light smoker	heavy smoker
1	0.44	0.46	0.37	0.44
2	0.44	0.5	0.42	0.25
3	0.43	0.51	0.43	0.4
4	0.56	0.58	0.48	0.27
5	0.85	0.85	0.76	0.34
6	0.68	0.72	0.6	0.62
7	0.96	0.93	0.82	0.47
8	0.72	0.86	0.72	0.7
9	0.92	0.76	0.6	0.6
10	0.87	0.65	0.51	0.54

SUMMARY
Groups	mean	st dev
nonsmoker	0.687	0.209287
former smoker	0.682	0.167451
light smoker	0.571	0.155167
heavy smoker	0.463	0.151954

Calculate the ratio of largest sample standard deviation to smallest sample standard deviation.

Is the criterion for the equality of variances met?  

Enter this data into L₁, L₂, L₃, L₄ and select ANOVA. Use the results to fill out the ANOVA table:

Source	df	SS	MS	F	P-value
Factor
Error
Total

Conclusion? Are the mean testosterone levels significantly different among these groups? Answer yes or no. Use α = 0.05.

Answer 1

the ratio of largest sample standard deviation to smallest sample standard deviation = 0.209287/0.151954 = 1.3773

there is no criterion for the equality of variances met

the mean testosterone levels significantly different among these groups