Answer:
The probability that a fair coin lands tail up is 1/2, which is equal to 0.5.
Step-by-step explanation:
There are two possible outcomes when a coin is flipped (saving for the case when the coin lands on its side.)
- The coin lands head-up;
- The coin lands tail-up.
If the coin is fair, the two outcomes should be equally likely. In that case, apply the following formula:
[tex]\begin{aligned}&\text{Probability that the coin lands tail-up}\\ =&\frac{\text{Number of outcomes that the coin lands tail-up}}{\text{Total Number of equally-likely possible outcomes}}\\=&\frac{1}{2} \\=& 0.5 \end{aligned}[/tex].
Credit for the phrasing of this probability formula goes to the Khan Academy article "Probability: the basics".
