Question

the probability that the dog bites the mailman is 0.21. find the probability that the dog does not bite the mailman.

Explanation:

Step1: Recall probability rule

The sum of the probability of an event happening and not - happening is 1. Let $P(A)$ be the probability of the dog biting the mailman and $P(\overline{A})$ be the probability of the dog not biting the mailman. So $P(A)+P(\overline{A}) = 1$.

Step2: Solve for $P(\overline{A})$

We know that $P(A)=0.21$. Then $P(\overline{A})=1 - P(A)$. Substitute $P(A) = 0.21$ into the formula: $P(\overline{A})=1 - 0.21$.
$P(\overline{A})=0.79$

Answer:

$0.79$