I am unsure what kind of a hypothesis test to use in my case:
So we are filling 500 ml bottles with water;
It's a known fact that before a max of 3% of all the bottles could be under-filled;
Now I took a sample of 180 bottles and 8 of them were under-filled.
With a significance level of 0.05, can we say that the percentage has changed?
Hypothesis: percentage has changed