In a debate on the alteration of a traffic system in the city centre, measurements of the number of cars per minute were taken at two junctions; the results were as shown in Table 2.19. Compare the...

In a debate on the alteration of a traffic system in the city centre, measurements of the number of cars per minute were taken at two junctions; the results were as shown in Table 2.19.

Compare the two distributions by plotting out their frequency polygons, and determine the means and standard deviations.