Exercise 6 Page 929

We want to find the probability of not living in a particular dorm. Note that this is the complement of living in that particular dorm. The sum of the probability of an event and the probability of its complement is 1. P(Event)+P(Not event)=1 The experimental probability of living in that particular dorm is 75 %. Let's now find the probability of its complement, which is not living in that dorm.

P(Particular dorm)+P(Not a particular dorm)=1

Substitute

P(Particular dorm)= 75 %

75 %+P(Not a particular dorm)=1

▼

Solve for P(Not a particular dorm)

WritePercent

Convert to percent

75 %+P(Not a particular dorm)=100 %

SubEqn

LHS-75 %=RHS-75 %

P(Not a particular dorm)=100 %-75 %

SubTerm

Subtract term

P(Not a particular dorm)=25 %

The probability of not living in a particular dorm or living in another dorm, is equal to 25 %.