# Resolved: Doubts in Exercise z Value

Exercise solution attached to this lesson I have doubts regarding the z value we find.

So we are finding 10% significance which means we have to find **z(0.45) i.e alpha = 0.9** value whereas in exercise we are finding **z(0.05) i.e alpha = 0.1** which is for 90% significance

z(0.45) = (-0.13)

z(0.05) = (1.65)

Z = -4.67 > -0.13 (although the Answer Remains the same that we reject Ho)

Please clarify

The level of significance is denoted by alpha. If we want 10% significant level, we set alpha = 0.10.

Eugene I'm not satisfied with your reply

Lets see previously we take 99% or 95% significance alpha gone be 0.01 and 0.05 respectively so in that way for 10% significance alpha gone be 0.9

Hi Mayank,

I do not have the script of the lesson you are referring to, I simply guess that when you are talking about "previously we take 99% or 95% significance", are you referring to 99% (or 95%) confidence, instead of significance?

If it is about 99% confidence interval, then we take alpha = 0.01 (This is similar as 1% level of significance); and similarly, for 95% confidence, we take alpha = 0.05 (5% level of significance).

Hope this helps, and sorry if I am in the wrong direction in answering your query.