Select all of the following scenarios below that contain nonbiased samples. Select all that apply:
✓ To estimate the political party distribution of residents in his state, Frank collects data from a large group of
randomly selected residents of his city.
✓ To estimate the mean number of classes that students take at his university, Samuel collects data from a
randomly selected proportionate number of students from each grade level.
David wants to estimate the mean grade point average of students at his school. He collects data by recording the
grade point average of every 25th student on the list of students after a randomly selected first student
Helen wants to estimate the male to female ratio of the residents of her city. She collects data by recording the sex
of every 50th resident after selecting a random starting point on a list of residents,

b.) To estimate the mean number of classes that students take at his university, Samuel collects data from a  randomly selected proportionate number of students from each grade level.

c.) David wants to estimate the mean grade point average of students at his school. He collects data by recording the grade point average of every 25th student on the list of students after a randomly selected first student.

d.) Helen wants to estimate the male to female ratio of the residents of her city. She collects data by recording the sex  of every 50th resident after selecting a random starting point on a list of residents.

Why? Because a sample is only biased if some individuals of the population are more or less likely to be chosen than others.

The sample from choice B isn't biased because every student has the same opportunity of being selected. It's the same predicament with choice C; it's also non-biased because again, each student has a chance of being in it, there is no preference.

And finally, the sample from option D is non-biased, because every resident that is being selected has an equally fair chance of being selected at random.

Hope this helps ;)

an altitude of 15,000 feet

step-by-step explanation: