Question

Find the critical value zo/2 that corresponds to a 72.5 percent confidence level. SEI A) B) C) D) Za/2 = -1.152 Za/2 = ±-1.172 E) F) None of These Zn/2-+-1.022

Answer 1

Solution:

Find the critical value $z_{\frac{\alpha }{2}}$ that corresponds to

a. 72.5 percent confidence level.

Answer: The correct option is:

B) $\boldsymbol{z_{\frac{\alpha }{2}}=\pm -1.092}$

Explanation:

We are given:

Confidence level = 72.5% or 0.725.

Therefore, the significance level $\alpha= 1 - 0.725 = 0.275$

$\large z_{\frac{\alpha }{2}}=z_{\frac{0.275}{2}}=z_{0.1375}$

Now we can use excel to find the two critical values. The excel function is:

$\large =NORMSINV(0.1375)=-1.092$

Therefore, option B) is correct.