Question

Consider the one-sided confidence interval expressions for the mean of a normal population. Round your answers to 2 decimal places. (a) What value of z Subscript alpha would result in a 85% one-sided confidence interval

Answer 1

`Z_(\alpha) = 1.035`

Explanation:

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

`\alpha = 1 - 0.85 = 0.15`

Now, we have to find z in the Ztable as such z has a pvalue of
`1-\alpha`.

So it is z with a pvalue of
`1-0.15 = 0.85`, so
`z = 1.035`

The answer is:

`Z_(\alpha) = 1.035`