UPDATE 3/12/13: There have been some great, and very creative, responses so far – thanks. Translating a “real-world” percentage into an experiment, and determining the possible outcomes, is a significant challenge! In many cases I’ve asked a question or made a suggestion — if you respond to my comment appropriately, I’ll give you extra credit for this assignment. Here are some tips, based on what I’ve seen so far:
- The Experiment should describe a process that could result in one of several outcomes.
- The Outcomes describe the different possible things that could happen. There should always be more than one outcome. Often, news articles will focus on something that already happened (as if the experiment already took place), and so we may already know what outcome was obtained in that particular case, and it’s easy to think of this as “THE outcome” — but there is always something else that could have happened, and might happen if the experiment were repeated. Don’t forget this ‘other outcome’.
- If your example began with a percentage, this will almost always be the probability that one of the outcomes will happen. Take a look at your experiment/outcomes — does this fit?
Probability is an idea that shows up very often in the world outside our math classroom. It occurs whenever a chance of something happening is described, often as a percentage (“a 90% chance of rain”), but sometimes in other forms (“a 9 out of 10 chance”). However, it is not always simple to see how the basic setup described in class applies to one of these situations — that is, to think of probability in terms of an experiment, with various outcomes.
Recall that an experiment is a process which, when carried out, results in just one of several possible outcomes. The outcomes are simply the different results that can occur.
Here are some examples from the news:
According to weather.com, there is a 10% chance of rain on Thursday, March 14 (at least, this is the percent reported on Wednesday, March 6).
The experiment: we wait and see what the weather is like on Wednesday, March 6.
Outcomes: it rains, it doesn’t rain.
“Spanish researchers have completed the first human trial of a new vaccine against HIV. It has been successful in 90% of the HIV-free volunteers during phase I testing. This vaccine brings great hope to eradicate this plague forever.”
The experiment: HIV-negative people are given the vaccine, and then are tested to see if they can contract HIV when exposed.
Outcomes: They do not contract HIV (the vaccine was successful), or they do contract HIV (the vaccine was unsuccessful).
Assignment (Due Thursday, March 14): Find an example of probability in the news. Reply to this post including the following:
- A brief description (what is it about?).
- A link to news story or article.
- Describe the experiment to which the probability refers.
- Describe the outcomes of the experiment.
NOTE: You may NOT use the same example as someone else – please check the existing responses before you submit yours.
Extra Credit: For extra credit, choose an example from your own major or intended career. At the end of your submission, include the words “Extra Credit:” followed by a brief description of how the example relates to your major/career choice.