In a program designed to help patients stop​ smoking, 156 patients were given sustained​ care, and 84.1​% of them were no longer smoking after one month. Use a 0.01 significance level to test the claim that 80​% of patients stop smoking when given sustained care. I have solved the test statistic and it is correct but I just need the p- value for the hypothesis test. Thanks in advance!
Upper H 0​: p equals 0.8
Upper H 1​: p not equals 0.8
The test statistic is 1.28.
The p value for this hypothesis is ?