Assume that z is the test statistic. (Give your answers correct to two decimal places.)

(d) Calculate the value of z for Ho: ì = 81, ó = 13.3, n = 51, x = 79.7.
-1.16 is my answer and it is wrong, can someone tell me how I missed this one, done several and got them right but not this one.

5 answers

Yes. your anwser is wrong.
In case you think I did not work it and just put a number down I worked it like this 79.7-81 over 13.3sqrt 51=-1.3/1.8623 so did I put the formula in wrong or what, I got all the other ones right with this formula?
z= (79.7- 81)/(13.3/sqrt(51))

z= -1.3/1.862372512

z = -0 .698 or -0.70
Thank you, I am not sure how my calculator came up with that answer. But I had worked it out like you did.
because you multiply 13.3 sqrt (51) but it is division. 13.3/sqrt(51).