Consider the following. (Give your answers correct to two decimal places.)

Question

(a) Determine the value of the confidence coefficient z(á/2) for 1 - á = 0.87.
my answer .44 .

(b) Determine the value of the confidence coefficient z(á/2) for 1 - á = 0.91.
my answer 0.46.

Answer 1

For one tail, your answers look okay. For two tails, the values would be multiplied by 2.

Answer 2

So I used these answers .44 for the first one and it was wrong then I multiplied 0.46 and used 0.92 and that one was wrong. Any suggestions??

Answer 3

We have been at this question for three hours and each time we each come up with different answers...