2-6 Probability Theoretical & Experimental

Probability – how likely it is that something will happen – Has a range from 0 – 1 – 0 means it definitely will NOT happen – 1 means it definitely WILL happen – Anything in between is a FRACTION

0 1 impossible definite less likely more likely

Outcome – the result of a single trial – Ex. Rolling a set of dice once Sample Space – lists all possible outcomes Event – another name for an outcome

Sample Space for rolling a pair of dice.

Theoretical probability is a calculated value Ex. The probability of tossing a coin and getting heads is ½. Does this mean that 1 out of every 2 tosses will be heads?

Theoretical probability is determined by: # of favorable outcomes # of possible outcomes

Experimental Probability Comes from repeated observations of the same trial is determined by: # of times an event occurs # of times trial is done

Odds Similar to probability Most often used in gambling situations Calculation # of favorable outcomes # of unfavorable outcomes