Which of the following scenarios contain biased samples?

Choose all that apply.

To estimate the ethnic background distribution of residents of his town, Charles collects data from1000

randomly selected town residents by using a random number generator.

To estimate the political party distribution of residents in his state, Joseph collects data from a large group of randomly selected residents of his city.

Victor wants to estimate the mean number of calories consumed by students at his school. He collects data from randomly selected individuals in the cafeteria for breakfast.

Howard wants to estimate the mean weight of people in his town. He collects data by interviewing members of a fitness club.