Math students estimate probabilities

Sisters scholars test probability. Photo by Conrad Weiler

Sisters' lunch time scholars got to play the odds last week.

Central Oregon Community College Math Professor Monte Cheney presented three problems in probability to a Lunch and Learn class at Sisters COCC on Thursday, October 31.

First was the "Monty Hall' three-door problem.

"There's a big prize behind one of the doors," said Cheney. "You pick one, but before you see what is behind it, you are shown that the good prize is not behind one of the other doors.

The problem -- two doors remain -- your first choice and one other door. Should you switch or stay and what are the odds?"

A card game scenario showed them how the odds swing in favor of a correct guess with the elimination of just one variable.

The four-tire problem was next for students.

"Four students claim they missed the exam at COCC because their car had a flat tire coming back from Portland. Questioned individually which tire was at fault ­ what are the chances they would all select the same tire correctly when questioned by the Prof?"

Four dice were used to represent tire "guesses" by chance.

The class consensus was there was only a 1.5 percent chance that all four students would be able to guess the correct flat tire. Therefore, if they agreed on which tire went flat, they were probably telling the truth.

Monte Cheney has been at COCC for five years teaching statistics and probability.

"I teach in business classes where we try and show that better solutions may be possible by using simulations of actual events," said Professor Cheney.

"An example might be in overbooking air flights and attempting to make a correct decision."