Homework 7: Hypothesis Tests for 2 Independent
Populations due Fri 4/5 at 12 pm (noon)
*Submit your homework to your TA’s mailbox (and Canvas if you wish) before the due date/time. The
mailboxes are to the left as you enter the Medical Science Center (1300 University Ave.) from the main
University Ave. entrance.
*No late homework will be accepted for credit.
*If a problem asks you to use R, include a copy of the code and output. Please edit your code and output to
be only the relevant portions.
*If a problem does not specify how to compute the answer, you may use any appropriate method but show
the work that is necessary for the TA to follow and evaluate your reasoning. I may ask you to use R or
manual calculations on exam, so practice accordingly.
*Staple multiple papers together; present solutions to all prompts clearly; and put the discussion you attend
on top to get full “Completion Points”.
Total Points: 45 Completion Points: 10; Accuracy Points: 35
A reporter for Time Magazine was interested in residents’ levels of worry about being the victim of
crime in their neighborhood. They performed a telephone poll of 500 adult Americans, 140 from urban
areas, 160 from suburban, and 200 from rural areas. The number of adults who reported worrying
about being a victim of crime was urban:83, suburban: 92, and rural: 86.
Perform a hypothesis test at the 5% level of significance to determine if there is evidence of a
difference in the proportion of urban and suburban residents who worry about being the victim of