Thousands of motorists travel on Highway 27 everyday. Before installation of traffic cameras at mile marker 11, motorists' speeds averaged 72 mph. After installation of cameras, speeds averaged 67 mph. An independent samples t-test comparing the average speeds yielded a t-statistic of 1.02. Remember, the critical value at p=.05 is 1.96. Assuming our data meet the requirements for conducting a t-test, what can we conclude? a. It is unlikely that the difference in the means was due to chance. b. There is a 95% chance that we would have observed this average difference if there really wasn't a
Thousands of motorists travel on Highway 27 everyday. Before installation of traffic cameras at mile marker 11, motorists' speeds averaged 72 mph. After installation of cameras, speeds averaged 67 mph. An independent samples t-test comparing the average speeds yielded a t-statistic of 1.02. Remember, the critical value at p=.05 is 1.96. Assuming our data meet the requirements for conducting a t-test, what can we conclude?
a. It is unlikely that the difference in the
b. There is a 95% chance that we would have observed this average difference if there really wasn't a difference in average speeds before and after the camera was installed.
c. We cannot draw any conclusions because we should have used a one-sample t-test.
d. We cannot draw any conclusions because the p-value is not reported.
e. We do not have enough information to draw any conclusions.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
