For the following, what inferential statistical procedures should be performed and what is the key information for answering the research question? Unless described otherwise, assume scores are parametric.

(a) To test the influence of dietary fat levels on visual accuracy, rats are placed on one of four different diets. Three weeks later, all are tested for visual accuracy.

(b) We measure the preferences of three groups of students for their classmates after either 1, 5, or 10 weeks into the semester. To be friendly, everyone’s scores are skewed toward being positive.

(c) To examine if body image is related to personality traits, we measure the self-confidence and degree of obesity in a sample of adults.

(d) We find that among all Americans without marital problems, people nod their head 32 times during a conversation with a spouse. In a sample of people having problems, the mean number of nods is only 22, with sX = 5.6.

(e)        We select 30 left-handed and 30 right-handed men and measure their manual dexterity scores. Ten of each type is tested under either low, medium, or high illumination levels.

(f) Last semester a teacher gave 25 As, 35 Bs, 20 Cs, 10 Ds, and 10 Fs. According to college policy, each grade should occur 20% of the time. Is the teacher different from the college’s model?

(g) We compare the introversion of two groups of autistic children, one after receiving a new improved therapy and the other after traditional therapy.

(h) To determine if handedness is related to aphasia, in a sample we count the number of left- and right-handed individuals and in each group count those who do and do not exhibit aphasia.

(i) We create two groups of 15 participants, who either slept 4 or 8 hours the night before. Then we rank their driving ability.

(j) To determine how colors influence consumer behavior, we compare the mean attractiveness scores from a group of participants who viewed a product’s label when printed in red, in green, and in blue.

(k) Does chewing gum while taking an exam lead to better performance? We obtain exam grades for students who do or do not chew gum during an exam, when the exam is either multiple choice or essay.