Question

fill in the blank with an appropriate word, phrase, or symbol(s).
if the probability that an event occurs is 0.8, the probability that the event does not occur is ________.

the probability the event does not occur is <image>.
(type an integer or a decimal.)

Explanation:

Step1: Recall the probability formula

The sum of the probability of an event occurring ($P(E)$) and the probability of an event not occurring ($P(\overline{E})$) is $1$. So, $P(E)+P(\overline{E}) = 1$.

Step2: Substitute the given value

Given $P(E)=0.8$. Substitute into the formula: $0.8 + P(\overline{E})=1$.

Step3: Solve for $P(\overline{E})$

Subtract $0.8$ from both sides: $P(\overline{E})=1 - 0.8$.
$P(\overline{E})=0.2$.

Answer:

$0.2$