Probability question - don't know how to do .?
Ho : mean = 25
Ha :mean > 25
You decide to reject Ho if the sample mean sales x > 26 and to accept Ho otherwise
(a) Find the probability of a Type I error, that is, the probability that your test rejects Ho when in fact mean = 25 dollars.
(b) Find the probability of a Type II error when mean = 28 dollars.This is the probability that your test accepts Ho when in fact mean = 28.
(c) Find the probability of a Type II error when mean = 30.
(d) The distribution of sales is not normal because many customers buy nothing. Why is it nonetheless reasonable in this circumstance to assume that the sample mean sales X will be approximately normal?