Question

what does the notation $z_{alpha}$ indicate? the expression $z_{alpha}$ denotes the z - score with an area of $alpha$ to its left. between $-z_{alpha}$ and $z_{alpha}$ to its right.

Explanation:

In the standard normal distribution, the notation $z_{\alpha}$ represents the z - score such that the area to the right of it under the standard - normal curve is $\alpha$.

Answer:

to its right.