Professor Mary Mancini studied class level and drinking behaviour at Rocky Mountain University in Red Deer,Alberta.At Rocky Mountain,every student is required to live in one of six 20-story dormitories,and every student has a single room.All dormitory room phone numbers begin with the prefix 747 or 757 (e.g.,phone numbers are 747-0001 to 757-9999).She used the student telephone directory and,after a random start,selected every fifteenth student.She then mailed a questionnaire to the 1000 students selected and had two follow-up postcard reminders.A total of 900 students returned questionnaires.Later,Professor Mancini asked the university registrar's office whether any students were omitted from the directory. About how many students are listed in the Rocky Mountain University student telephone directory?
A) 2000
B) 10 000
C) 15 000
D) 20 000
E) 35 000

Question

Quizplus · Accepted Answer

Since Professor Mancini selected every fifteenth student after a random start, it means that there were a total of 15,000 students listed in the telephone directory (1000*15). This assumes that every student in the directory is assigned a unique phone number, with no missing numbers, and that the directory is up to date. The question about whether any students were omitted from the directory is not relevant to determining the number of students listed in the directory.

Professor Mary Mancini Studied Class Level and Drinking Behaviour at Rocky