The random sample of 900 taxpayers was taken to find average state income tax paid by citizens. 95.5% confidence interval estimate was created and found to be
P(200< µ<1400)=95.5%
i) Find Z-score related with 95.5% level of confidence?
ii) Find standard deviation of sampling distribution oXbar, for samples of size n=900?
iii) Find population sandard deviation ox for all taxpayers?