A study was performed to observe the calories per day an Average American consumes. 58 people were surveyed, and the results yielded an average calorie count of 2425.25, with a standard deviation of 325 calories.

1. What is the variable? (2)

1. What are the observational units? (2)

1. What is the value of n? (1)

1. Write the parameter of interest in words. (2)

1. Write the statistics? (2)

1. Write the null hypothesis in words AND symbols. (4)

f) Find the confidence interval. Interpret it. (4+2)

The General Social Survey (GSS) is a survey administered every two years to a random sample of adult Americans aged 18 and older. The survey asks a battery of questions focused on different social aspects of the population. In 2018, one of the questions was whether or not the adult lived in a different state from where they were born. Of the 2,348 surveyed that year, 36.2% replied that they do currently live in a different state from where they were born.

1. What is the variable? (2)

1. What are the observational units? (2)

1. What is the value of n? (1)

1. Write the parameter of interest in words. (We are interested in) (2)

1. Write the statistics? (2)

1. Write the null hypothesis in words AND symbols. (4)

f) Find the confidence interval. Interpret it. (4+2)

3. A study done in France (Uffler et al., 2017) explored whether there is an association between a student's intrinsic motivation and where they sit in class. More specifically, they randomly selected 593 health science students (mostly nursing students) in 9 different classrooms by giving them a questionnaire that measured their intrinsic motivation. (Those that are intrinsically motivated do things because that is naturally satisfying to them and they don't need an external reward.) The researchers also noted the distance each student sat from the front of the class.

1. Is this an observational study or an experiment? Explain why. (1+1)

1. What are the observational units? (1)

1. What is the explanatory variable? Is it categorical or quantitative? (1+1)

1. What is the response variable? Is it categorical or quantitative? (1+1)

1. Did this study involve random sampling? If yes, what is the advantage? If no, what is the disadvantage? (1+1)

f. The researchers found that students who sat closer to the front of the class tended to have higher intrinsic motivation scores. Is this claim justified? Why or why not? (2)