Question

Find the z-value needed to calculate one-sided confidence bounds for the given confidence level. (Round your answer to two decimal places.)

a 81% confidence bound

Answer 1

Contidence level =81%= 0.81

Area =0.81

( Check closer value value in the middle of the table we get 0.8106 this is more closer value consider row and column number which is 0.8 and 0.08 so we get 0.88 or use Excel command

=Normsinv(0.81) )

So for one tailed test at 81% confidence interval we get

Z value = 0.88

For two tails we get

Area =1 - 0.095 = 0.905

Check this area in table we get

Z = 1.31

For two tails we get z value is 1.31