MAT 407

Hand-in assignment #4

Due Thursday, October 13

 

Read the article “Driving While Black: A Statistician Proves That Prejudice Still Rules the Road” by John Lamberth.  Answer the questions, typed and in paragraph form (i.e. complete sentences), based on this article and what you know about probability.

 

  1. Give a short summary (no more than, say, 5 or 6 sentences) of the article in your own words.

 

  1. The author conducted a study on the NJ Turnpike to try to determine the percentage of African Americans in what the author refers to as the “turnpike population”.  How was that study done?  What was that percentage?  Note that this percentage is not the percentage of drivers who are African American, but the percentage of all those riding in cars on the highway who were African American.

 

  1. Another component of the NJ study was to try to estimate the percentage of drivers on the road who were speeding.   Describe how that was done – why does the author refer to this as the “rolling survey”?  What percentage of cars on the road were speeding?  What percentage of the speeders were African American?

 

  1. Let Sp= the driver was speeding and let A= the driver is African American.  If our sample space consists of all drivers on the NJ Turnpike, express the percentages you identified in question 3 in terms of probabilities involving these two events (note that one of them should be a conditional probability.)  

 

  1. The author used police records to determine the race of those pulled over.  What did he find?  Based on the percentages, do you believe that the events A: the driver is African American and PO: the driver was pulled over are independent?   In order to answer this question in terms of probability, you may interpret the percentage found in question 2 as P(A), even though as we noted it is not strictly speaking the percentage of drivers who are African American.

 

  1. The author then used police records to determine the race of those pulled over and arrested who were African American.  Based on the percentage given, do you believe that race is independent of being arrested at a highway stop?  Explain.

 

  1. How were the results of this study used in a court of law?

 

  1. Several years after the NJ study, the author did a similar study in Maryland.  Briefly summarize what the author found.  Did these results contradict the results of his NJ study, or corroborate them?