Question

Define the z_α (z alpha) notation for z critical values of the standard normal distribution Z and

determine for α (alpha) = 0.0055.

Answer 1

$\alpha =0.0055$, thus, $Z_\alpha=Z_{0.0055}$. We use the following command in $R$ to get its value,

z=qnorm(0.9945)

The output for this command is,

> z

[1] 2.542699

Therefore, $Z_{0.0055}=2.542699$. This is the value that leaves an area of 0.0055 to the right of the standard normal tables.