Question

Find the value Z a/2 needed to construct a confident
interval with the given level of 99.7%

Answer 1

Answer:

The critical value is $Z_{\frac{\alpha}{2}} = 2.96$

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.997}{2} = 0.0015$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$.

That is z with a pvalue of $1 - 0.0015 = 0.9985$, so Z = 2.96.

The critical value is $Z_{\frac{\alpha}{2}} = 2.96$