In: Statistics and Probability
The District of Columbia Police Department are gathering highway speed data along a section of the Capital Beltway to determine if the current speed limit is being followed. A radar speed detection device is used to measure the speeds of cars on the expressway. The speeds are normally distributed. The speed gun captures the speed of 6 vehicles as 80mph, 70mph, 100mph, 70mph, 80mph and 80mph.
c)
Sketch a normal distribution diagram to illustrate the mean and standard deviation, indicating clearly the mean and the speeds within one, two and three standard deviations of the mean.
Ans: Within one standard deviation of the mean
Within two standard deviations of the mean
Within three standard deviations of the mean