Cotinine levels were measured in a group of non-smokers exposed to tobacco smoke (n =40), the mean of the sample was 60.58 ng/Ml and the standard deviation was XXXXXXXXXXng/Ml. Also, cotinine levels...

Cotinine levels were measured in a group of non-smokers exposed to tobacco smoke (n =40), the mean of the sample was 60.58 ng/Ml and the standard deviation was 138.08 ng/Ml. Also, cotinine levels were measured in a group of non-smokers not exposed to tobacco smoke(n =40), the mean of the sample was 16.35 ng/mL and the standard deviation was 62.53 ng/mL. Cotinine is a metabolite of nicotine, meaning that when nicotine is absorbed by the body, cotinine is produced. Use a 0.05 significance level to test the claim that non-smokers exposed to tobacco smoke have a higher mean nicotine level than nonsmokers not exposed to tobacco smoke.

a)Define the parameter and state null and alternative hypothesis

b)Test Statistics

c) Critical Value Approach

d) Conclusion