Final answer:
The percentage of the area under the normal curve that lies to the left of the mean (μ) is 50%.
Step-by-step explanation:
The percentage of the area under the normal curve that lies to the left of the mean (μ) is 50%. This is because the normal distribution is symmetric, so half of the area lies to the left of the mean and the other half lies to the right.
For example, if we consider a standard normal distribution with a mean of 0 and a standard deviation of 1, about 50% of the values will be less than 0 and about 50% will be greater than 0.