Look on your normal chart at the number corresponding to 2.15. you get .9842. 1-.9842=.0158 , which is your p-value. Your decision to reject the null hypothesis will be based on what level of signifigance you want. Here, for a .01 level of sig, you cannot reject the null because .0158>.0100. Or you can look at it like this: 2.33 is the Z corresponding to .01(1-.01=.99) level of sig. Your test stat is smaller than 2.33, therefore does not fall into the rejection region.