Distribution of Highway Traffic Speeds, Fitting to a Normal Distribution

Abstract

Observations were made of the speeds of vehicles passing a point on the highway using a radar speedmeter. Calculate the mean speed, the standard deviation of the observed speeds, and the 85 percentile speed. Show whether the distribution of speeds can be represented by a normal distribution. The observations are given in Table 2.1 in the form of a list of speed classes (column 1) and the observed number of speeds in each class (column 2).