Please explain all of them and do not show these answers to other students?

A ). A large corporation wants to find out which benefits plan its employees would prefer. Which one of the four procedures listed below would be most likely to obtain a statisticamployeeslly unbiased sample? Explain your reasons why. [10 Points]

a. survey a random sample of employees from a list of all employees b. invite all employees to indicate their choices by email c. place suggestion boxes at random locations in the companys plant and offices d. assemble a group with one member from each department and record the preference of these

B): A university polled 500 of its students, randomly selecting them proportional to the number of students enrolled in each degree program. Which sampling method did the university use? Choose from the one below and explain your answer. [10 Points]

a. simple random b. stratified c. convenience d. systematic e. voluntary response

C ). To do market research, a telemarketing firm randomly selected 1000 names from a stores database and contacted them. Which sampling method did the university use? Choose from the one below and explain your answer. [10 Points]

a. simple random b. stratified c. convenience d. systematic e. voluntary response

D). To get reactions about a particular new car, readers of a car magazine were asked to mail in their answers to a survey. Which sampling method did the university use? Choose from the one below and explain your answer. [10 Points]

a) simple random b). stratified c). convenience d) systematic e) voluntary response