Question

Question 8

A traffic engineering study on traffic delay was conducted at intersections with signals on urban streets. Three types of traffic signals were utilized in the study: (1) pretimed, (2) semi-actuated, and (3) fully actuated. Five intersections were used for each type of signal. The measure of traffic delay used in the study was the average stopped time per vehicle at each of the intersections (seconds/vehicle). The data follow.

Pretimed	Semi-actuated	Fully actuated
36.6	17.5	15
39.2	20.6	10.4
30.4	18.7	18.9
37.1	25.7	10.5
34.1	22	15.2

Use the data from above to determine how many intersections the traffic engineer would need for each type of traffic signal to reject the null hypothesis at the .01 level of significance with a power of .90 if mean delays at the three traffic signal types were 20, 18, and 16 seconds, respectively.

Answer 1

Solution-

we can perform an anova analysis to check the hypothesis that

H0 : There is no difference in the mean delays at the three traffic signal types .

H1 : There is a difference in the mean delays times in atleast one type of signal of all 3 types of signal

we shall conduct the test at an alpha of 0.01, the setup in excel is as follows

here we see that The p value = 1.18E-06 is less than 0.01 , hence this is the strong evidence against the null hypothesis therefore we can reject the null hypothesis in favor of alternate hypothesis and conclude that There is a difference in the mean Delay times in atleast one type of signal of all 3 types of signal .

Note-

If it helps you then please appreciate the work.