Question

Although tea is the world’s most widely consumed beverage after water, little is known about its nutritional value. Folacin is the only B vitamin pres

Significance tests
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asked 2021-06-18

Although tea is the world’s most widely consumed beverage after water, little is known about its nutritional value. Folacin is the only B vitamin present in any significant amount in tea, and recent advances in assay methods have made accurate determination of folacin content feasible. Consider the accompanying data on folacin content for randomly selected specimens of the four leading brands of green tea. Brand 1234amp; Observations amp;7.9amp;5.7amp;6.8amp;6.4amp;6.2amp;7.5amp;7.5amp;7.1amp;6.6amp;9.8amp;5.0amp;7.9amp;8.6amp;6.1amp;7.4amp;4.5amp;8.9amp;8.4amp;5.3amp;5.0amp;10.1amp;amp;6.1amp;4.0amp;9.6amp;amp;amp;
(Data is based on “Folacin Content of Tea,” J. Amer. Dietetic Assoc., 1983: 627–632.) Does this data suggest that true average folacin content is the same for all brands? a. Carry out a test using \(\alpha:=.05\) via the P-value method. b. Assess the plausibility of any assumptions required for your analysis in part (a). c. Perform a multiple comparisons analysis to identify significant differences among brands.

Answers (1)

2021-06-19
a) Reject null hypothesis;
b) It is plausible to assume normality and equal variances;
c) The pairs that do not differ signifcantly from each other are (1,2),(1,3),(2,3),(2,4),(3,4)
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