Stating hypothesis null hypothesis (h0) the claim tested by a statistical test; designed to assess strength of evidence against null hypothesis. N) ~ n(0,1) if h0 is ture the null hypothesis h0 were true. Test for a population mean data that would rarely occur if the null hypothesis h0 were true provide evidence that h0 is not true. P-value gives us the probability that it would rarely occur. Example 1) a bag of chips says that theres 200 chips in the bag. We examined 5 bags of chips, w/ standard deviation of 15. 65. H0: = 200 ha: < 200. = 181 200/ 15. 65/sqrt5 = -2. 71 --> table a --> p value = 0. 0034. Since pvalue < a , we can reject h0, that 200 is the average amount of chips in the bag. If we want to find ha > it"ll be a different calculation. Assume values are same for all values from above but ha > .