Question 1 [15 points]
For the following four scenarios determine if you should use I) One sample t-test II) Two sample t-test III) Paired sample t-test IV) ANOVA for comparing group means. For each scenario state the test you would use and briefly justify your choice of test.
I
A sample of 250 different 150 mL bottles of Coca-Cola was collected and the volume of each bottle determined. The bottling plant would like to know if the mean fill volume significantly differs from 150 mL.
II
Thirty mutually exclusive and randomly selected 2-acre plots were evaluated for their tree density (total trees on the plot). After a period of 10 years, the same thirty plots were evaluated again. The forestry station would like to determine if the mean tree density in their region has changed over the past decade.
Ill
Retail sales data has been collected for 10 different, major retail companies located in America. The yearly retail sales for each company has been recorded over the past 15 years. A financial corporation is interested in knowing if the mean sales of the 10 different retail companies is equivalent over the past 15 years.
IV
Two species of water buffalo are competing for dominance over a region of land. A major factor in successful dominance is the distance traveled per day. Biologists have collected the mean distance traveled over a 2 week period for 35 buffaloes of each species. They would like? to determine if their is a significant difference in the mean travel distance between the two species.