Question

Determine the critical value.

Using the z-tables (or t-tables), determine the critical value for the left-tailed z-test with α=0.01

Question options:

	a)-2.326
	b)2.326
	c)2.576
	d)-2.576

Answer 1

a) -2.326

the given significance level is alpha = 0.01 α=0.01, for the left-tailed case.The z-critical value for a left-tailed test, for a significance level of alpha = 0.01 α=0.01 is,

zc=−2.326

(From the normal z-table)

Some more information about critical values for the normal distribution probability: First of all, critical values are points at the tail of a certain distribution and the property of these values is that the area under the curve for those points to the tails is equal to the given value of α.

For a left-tailed case, the critical value corresponds to the point to the left of the center of the distribution. They will have the the property that the area under the curve for the left tail (from the critical point to the left) is equal to the given significance level α.

The Curve for this is look like below ( Graphically ),

this is the simple graph of left tailed critical value for normal distribution.

Note : Here i am using the software, to calculate critical value you can use any Statistical software or normal z-table.

Hope you understood then RATE POSITIVE ?. In case of any queries please feel free to ask in the comment section.

Thank you.