Answer:
0.5
Explanation:
If you flip a coin, the probability of getting a head is 0.5 or 0.5 on the probability scale.
It is worth noting that when a coin is fair, the probability of getting a head or a tail is always 0.5 or 50%.
So in the probability scale you should place a cross on the point 0.5 which indicates the probability of getting a head.