Answer:
Mark's experimental probability may be different from the theoretical probability of spinning a coin due to several factors. First, the penny may not be perfectly balanced, which can affect how it lands. Secondly, Mark may have spun the penny with a particular technique or force, which can also affect the way the penny lands. Thirdly, the surface on which the penny is spun may not be perfectly level, which can introduce factors that affect the way it lands.
Overall, these factors can cause Mark's experimental probability to deviate from the theoretical probability, which assumes that the coin is perfectly balanced and spun randomly on a level surface. However, over a large number of spins, the experimental probability should become closer to the theoretical probability, as the effects of these factors average out.