A researcher is interested in comparing tastiness of different parts of cheese in grilled cheese sandwiches.  The researcher expects that Cheddar cheese grilled sandwiches are rated tastier than Swiss cheese grilled sandwiches.  This researcher needs to use a within-subjects design. Every participant tastes both Cheddar and Swiss cheese grilled sandwiches. Except for the types of cheese used in the grilled sandwiches, there is no difference among the two kinds of sandwiches. Participants indicate the degree of tastiness on a 10-point scale and the ratings appear in the following table. Tastiness scores tend to be skewed.

a.       What statistical test should be used to examine these data?

b.      Justify H₀ and H_a for this study.

c.       Conduct the appropriate analysis.

d.      Should H₀ be rejected? What should the researcher conclude?