Where in real life does the normal distribution occur, and where does it not? Provide specific examples with explanations why data is normally distributed or not.

The normal distribution is often encountered in natural and social phenomena where many independent factors influence the outcome.

Examples with a normal distribution:

• Human height: most people have an average height, while very tall or short individuals are less common. This is related to numerous genetic and environmental factors.
• Measurement errors: when measuring the same quantity multiple times, errors tend to be normally distributed due to random factors.

Examples where the normal distribution is not suitable:

• Population income: the distribution is often skewed to the right, as a small portion of people have very high incomes.
• Number of website visits: may have a Poisson or exponential distribution, as events (visits) occur randomly and independently.

Thus, the normal distribution is characteristic of data where the result is the sum of many independent random factors, and not for data with constraints or asymmetry.