Mr. Connelly, the school teacher-librarian, wants to purchase new books for the school
library. He has the following ideas for
collecting data:
A. Observe which books are most
commonly taken out, and buy more
books by the same authors.
B. Ask all the students who come into the
library what new books they would like
to have in the library.

C. Visit a Web site that lists the award-
winning books for the past three years.

D. Create a questionnaire to give to all the
students in the school, asking about
their favourite kinds of books.
a) Which ideas involve collecting primary
data?
b) Which ideas include a bias in favour
of students’ opinions?
c) Which idea includes a bias against
students’ opinions?

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.

17.08

correct me if i am wrong.