Question

(1 point) Given the significance level α=0.04α=0.04 find the following:

(a)    lower-tailed z value
z=

(b)    right-tailed zvalue
z=

(c)    two-tailed z value
Z

Answer 1

For the given the significance level α=0.04 the Z score for different tails is calculated with the help of excel formulas.

a) For a lower tail Z value, the excel formula for normal distribution used to calculate the Z value is '=NORM.S.INV(0.04)' which results in Z=-1.75

b) For the Upper Z tail value, the excel formula used is =NORM.S.INV(1-0.04) which yields the Z score as Z=1.74

Here we are using '1-0.4' in excel formula since the excel formula always gives the Z value or the P-value from the left of the normal curve.

c) FOr a two-tailed Z value, the excel value used is =NORM.S.INV(0.02) which results in Z=+/-2.05

Here we are using 0.02 instead of 0.04 value because of both the tail shares equal area in case of two-tail.