A police chief wants to determine if crime rates are different for four different areas of the city (East(1), West(2), North(3), and South(4) sides), and obtains data on the number of crimes per day in each area. The Tukey's confidence intervals are shown below. At the 1% significance level, the conclusion from Tukey's confidence intervals is we ________.
A) cannot conclude the mean number of crimes differs for West and East
B) cannot conclude the mean number of crimes differs for West and South
C) cannot conclude the mean number of crimes differs for South and North
D) cannot conclude the mean number of crimes differs for West and North

Question

A police chief wants to determine if crime rates are different for four different areas of the city (East(1), West(2), North(3), and South(4) sides), and obtains data on the number of crimes per day in each area. The Tukey's confidence intervals are shown below.  At the 1% significance level, the conclusion from Tukey's confidence intervals is we ________.
A) cannot conclude the mean number of crimes differs for West and East 
B) cannot conclude the mean number of crimes differs for West and South 
C) cannot conclude the mean number of crimes differs for South and North 
D) cannot conclude the mean number of crimes differs for West and North

Quizplus · Accepted Answer

The Tukey's confidence interval for the difference in means for West and North contains zero, which means we cannot conclude that the mean number of crimes differs for West and North. The other confidence intervals do not contain zero, meaning we can conclude that the means are different for those pairs of areas.

A Police Chief Wants to Determine If Crime Rates Are