Statistical Methods in Criminal Justice: Probabilities & Margin of Error

Respond to each with at least one paragraph for each, attached is how I want it to be displayed. 

Probabilities

We have learned that probabilities are a likelihood that something is going to happen.  It is not a certainty.  How does this type of statistic help us when conducting research in criminal justice?  How does it hurt the process?  Try and find examples to back your responses.

 Margin of Error

Many times when hearing on the news or reading about poll results, you will hear the margin of error.  Find a poll and discuss the margin of error related to the article that you found.  How is the margin of error used and what does it mean for statistics?