What does the notation zα represent in statistics?

The notation zα specifically indicates the z score corresponding to a specified area α in the right tail of the standard normal distribution. In statistical terms, when you refer to zα, you are identifying the critical value where the area to the right of this z score equals α. This is particularly useful in hypothesis testing and confidence interval formation, where one needs to determine the cutoff points that define certain probabilities under the normal curve.

In summary, zα is essentially the threshold for which the probability of obtaining a value greater than zα is equal to α, enabling statisticians to make informed decisions based on probability and standard scores.