The State Transportation Department is thinking of changing its speed limit signs.It is considering two new options in addition to the existing sign design.At question is whether the three sign designs will produce the same mean speed.To test this,the department has conducted a limited test in which a stretch of roadway was selected.With the original signs up,a random sample of 30 cars was selected and the speeds were measured.Then,on different days,the two new designs were installed,30 cars each day were sampled,and their speeds were recorded.Suppose that the following summary statistics were computed based on the data: The appropriate test to conduct to determine if the population means are equal is:
A)Hartley's F-max test.
B)one-way analysis of variance
C)three sample t-test.
D)randomized complete block analysis of variance.

Question

The State Transportation Department is thinking of changing its speed limit signs.It is considering two new options in addition to the existing sign design.At question is whether the three sign designs will produce the same mean speed.To test this,the department has conducted a limited test in which a stretch of roadway was selected.With the original signs up,a random sample of 30 cars was selected and the speeds were measured.Then,on different days,the two new designs were installed,30 cars each day were sampled,and their speeds were recorded.Suppose that the following summary statistics were computed based on the data:  The appropriate test to conduct to determine if the population means are equal is:
A)Hartley's F-max test. 
B)one-way analysis of variance 
C)three sample t-test. 
D)randomized complete block analysis of variance.

Quizplus · Accepted Answer

The best choice is one-way analysis of variance (ANOVA), which can be used to compare the means of more than two groups. In this case, the groups are the three different sign designs. Hartley's F-max test is used to compare the variances of multiple groups, but in this case, we are interested in comparing the means. A three sample t-test can only compare means between two groups at a time, and randomized complete block analysis of variance is more appropriate for experiments involving multiple factors or treatments. Therefore, the best choice is one-way ANOVA.

The State Transportation Department Is Thinking of Changing Its Speed