Hello. Could you explain me how to solve this hypothesis test:

Suppose you want to estimate the proportion () of population that had covid. To do so, you survey a random sample of people survey from 20 people shows the following answers: N,N,N,N,Y, N,N,N,N,N, N,N,N,Y,N, Y,N,N,N,N, where Y- yes (had covid), N-no (did not have covid). Test the hypothesis that for every 100 people, the number of people who had covid is fewer than or equal to 30 people (H0- null) at 10 % significance level.

Here, beta prior: a=1, b=1, prior mean=0.5, prior sd=sqrt(1/12)

beta posterior a1=2, b1=20, posterior mean=1/11, posterior sd= 0.06