Answer:
See Explanation
Step-by-step explanation:

It depends on how good the service was. it the service was really bad or just bad than maybe 2$, if the service was ok 5$ and finally if the service was extremely good and everything was just the way you like it then I would say tip 10$-20$
Answer:
Yes, the probability of seeing the sample result is so far from what is expected that the probability of it occurring by chance alone is very unlikely.
Step-by-step explanation:
I hope this is right