There has been concern for some time that nitrite present in cured meats may result in the formation of carcinogenic N-nitrosamines in the stomach by reaction with amines in the diet. It is possible to safely measure the amount of nitrosamine production in humans by administering a large dose of proline and measuring the level of N-nitroso-proline, a non-toxic reaction product, excreted in the urine. You decide to test the hypothesis that eating a reasonable amount of cured meat will increase the amount of nitrosation taking place in the stomach in the following way. Each of 6 subjects, who have been asked to avoid cured meats for the previous week, is given a dose of proline and the excretion of N-nitroso-proline is measured for 24 hours. Each subject is then fed a breakfast including 6 strips of bacon and a dose of proline; excretion of the nitrosated amino acid is again measured for 24 hours. You obtain the data listed below in the form (basal g excreted, g excreted after bacon).

Data: (3.1,2.8) (2.0,6.1) (5.1,4.5) (4.2,2.9) (8.5,8.9) (1.1,6.0)

What is the most appropriate statistical approach to test the hypothesis?

a. t-test for paired samples

b. t-test for unpaired samples c. ANOVA d. Mann-Whitney U test e. Kruskal-Wallis test

Did bacon consumption significantly increase the excretion of the N-nitroso-proline?