chapter 6 Flashcards
what is probability?
a numerical measure of the chance of an event happening
what is the formula for the probability of an event?
number of successful outcomes/ total number of possible outcomes
what is the formula for expected frequency of an event?
p(A) x number of trials
what is the expected frequency?
the number of times you expect the event to happen- it is not necessarily what will actually happen
what is a trial?
each experiment or response to a survey
what is the formula for estimated probability?
number of trials with successful outcomes/ total number of trials
what is the formula for risk of an event?
risk of event = number of trials in which event happens
what is absolute risk?
the probability of an event happening
what is relative risk?
how many more times likely an event is to happen for one group compared to another group
formula for relative risk?
n(those in the group)/ n(those not in the group)
what are mutually exclusive events?
if they cannot happen at the same time
if two events are mutually exclusive, how do you write the probability of either one happening?
P (A or B)
what is the formula for P(A or B)?
P(A) + P(B)
when is a set of events exhaustive?
when it contains all positive outcomes
when do you use the general addition law?
when events are not mutually exclusive
