Allan is a salesman at a local electronics store and receives an incentive for his performance. When customers arrive at the store, he accompanies them till they leave the store. He talks to them, shows them different equipment, and makes suggestions about accessories they may not have considered. Allan's behavior is best described as:

In a publicly held corporation, - o stockholders rarely trade their stocks o stocks are not usually traded at stock exchanges o a large number of stockholders can buy and sell stock o family members are excluded from holding stock

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a. a researcher uses the customs office’s passenger lists for ships bringing immigrants to the us between 1820-1845 to track the numbers of immigrants from certain ethnic groups. b. a researcher conducts a linguistic study of comments posted on a local public blog. c. a developmental psychologist videotapes interactions between groups of toddlers and their care givers to determine which intervention methods most effectively manage aggression. d. a researcher asks the director of a local free clinic about the number of patients in the last two years with newly diagnosed hiv/aids.

Donald is studying the eating habits of all students attending his school. he samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. he then collects data from the sample. which type of sampling is used? select the correct answer below: systematic sampling convenience sampling stratified sampling cluster sampling